They say, "When you're not sure what gift to give someone, always give them something you would want yourself." When I got married, I really didn't want anything (except the wife whom I got), but I sure could have used a picture frame specifically for wedding pictures...

...thus, when invited to my friend's wedding, this project was born.

Step 1: Materials, Costs, and Tools

The complexity and cost of this project will depend entirely on the materials selected. For clarity and brevity's sake, I will list a few alternative options, but only go into to detail on the method I chose.

FRAME:
1. You can build a picture frame entirely from scratch if you have the skills and the time. I don't and didn't, so I didn't.
2. You may be able to find a tri-fold picture frame available for sale the will fit your needs. I couldn't.
3. You can buy three pre-made frames (finished or unfinished) and 4 hinges with screws.
4. My choice:
(first and second images)
-One double-sided picture frame for the center piece ("L" Size): $1.00.
-Two identical unfinished folding picture frames ("L" Size): $2.00. This covered the left and right "wing" frames and provided 4 matching hinges. Also, being folding frames, they already had recesses cut-out to fit the hinges; meaning 4 fewer recesses I had to cut myself!

*** Check your local craft store like Michael's or Jo-Ann (go to Seria if you're in Japan!) to find unfinished frames of reasonable quality.

BACKING:
1. If you purchased frames that had decent quality backing from the get-go, just use it!
2. If the backing is sturdy but doesn't look right for you project, paint or otherwise resurface it!
3. My choice:
(third image)
-The frames I got had cheap corrugated backing, so I gathered-up some thick card-stock, natural fiber paper (saved wrapping paper!) and leather (from a worn-out coat) and made my own. All recycled materials: $0.00.

FINISH:
1. If you purchased frames that look good, leave them!
2. Stain, paint, decoupage, carve, or do whatever you have the skill to do.
3. My choice:
-I found inspiration in this great Instructable by blackbean, but substituted acrylic paints instead of spray paint (because it's what I work best with and had on hand). Leftover from other projects: $0.00.

CENTERPIECE:
1. Paint a design or write a message directly on (the inside of) the glass with appropriate glass paint or paint pens.
2. Print or hand-draw a picture, photo, message, abstract design, or whatever is in keeping with your taste.
3. Leave it open for a third photograph.
4. My choice:
-Write a poem in calligraphy; required paper, ink, and quills which I already had. Left over from other projects +parchment "recovered" from my parents' basement: $0.00.

TOOLS (all of which are pretty commonplace):
(fourth and fifth images)
*** I'll preface by saying NO ONE should use ANY tools with which they are not fully comfortable and qualified!!!
(except power tools: no matter how qualified, you should always be a little afraid of power tools...) ***
-Pencil -Ruler / Box Cutter / Cutting Mat -Rotary Tool w/small diamond grinding bit and SAFETY GLASSES / GOGGLES
-Paintbrush -Disposable Chopstick and Small Pry-bar (for opening and stirring paint)
-(Not Pictured) Hot Glue Gun -Tweezers

CONSUMABLES:
(not pictured)
-Glue Sticks *New: $1.00 / This Project:$0.20
-Double-Stick Tape *New: $1.00 / This Project: $0.35
-Old Newspapers *Free

TOTAL EXPENDITURE:
$3.55 for this project specifically.
+ $5.00-$10.00 if above-mentioned "left-over" materials had to have been purchased.
+$20.00-$30.00 if you don't own the tools.

PROJECT WORK TIME:
Approximately 10 hours including painting (but not drying time) and messing-up the first dozen drafts of the centerpiece.

Step 2: Disassemble

Assuming you're using prefabricated frames and you plan to re-finish them, they will need to be disassembled first.

The manner in which the frames you purchased come apart will vary, so it's best to examine how the frames come apart prior to purchase.

I'm going to assume you already know how to use a screwdriver and just say:
Be careful, go slowly, don't scratch or damage anything, and don't lose any parts.

Step 3: Recesses for the Hinges

This is easy to do if you don't care how the final results will look. I wanted the final product as "store-bought" looking as possible, however, so this was actually the hardest part. If you're not sure you'll be able to do this step well, it might be better to skip it and just attach the hinges directly to the side of the frame (if your hinges are really cool, that might not be a bad idea!).

Step 1:
Trace the area to which the hinge will be affixed. Making the recessed areas just slightly larger than the hinge is a good idea, but how much bigger is up to your aesthetic sense. In my case, the frames to which the hinges were originally attached had slightly over-sized recesses, so I measured and marked to match those.

Step 2:
Make shallow slices into the lines you drew in step 1 using a box cutter. Don't cut your finger or anything else.
These cuts will act as a guide for step 3.

Step 3:
Carve away the surface of the wood along the guides you sliced in step 2. Don't cut your finger or anything else this time either.
This cut should be slightly shallower than the thickness of the hinge.

Step 4a:
If you haven't already, put on your safety glasses.
Step 4b:
Finish the recess with a diamond grinding bit in your rotary tool. The target depth should be just the thickness of the hinge or slightly deeper to compensate for paint (if you plan to apply a thick coat).
Step 4c:
Without removing your safety glasses, allow the rotary tool to come to a COMPLETE stop and UN-PLUG it.
Step 4d:
Remove your safety glasses... or not... it's up to you at this point!
(I left mine on and went outside to water the garden and creep-out the neighborhood children coming home from school!)

Step 4: Painting

Again, I got the inspiration for this finish from blackbean's Instructable. Check it out!

Before Starting:
Sand and prime as appropriate. This will depend on the material of the frame and type of paint you plan to apply. If you're painting on anything other than raw wood (plastic, glass, ceramic, etc.), be sure to choose the correct primer for that material!

Step 1: Base Coat
Apply the base color taking care not to leave any brush strokes or uneven spots. As landscape oil painting is a hobby of mine, I'm quite practiced with the brush and have no problem. If you're not as confident, spray paint or a self-leveling paint like Hammerite might be a better choice. The second step will not work well if the paint is uneven.

LET DRY
REPEAT IF NECESSARY

Step 2: Rub-In the Top Coat
Take some of the gold paint on your finger (if it's acrylic) or an old sock or other piece of fabric. Rub the paint into the base coat color as though you're trying to get through it to the wood underneath (I ended up using both of my entire hands to really rub it in).

Remember, the goal is to make sure some of the base coat is showing through!

As you rub, you may get little boogers of paint forming on the surface; remove them with tissues and/or a clean, dry paintbrush.

Step 3: Seal it In
Varnish, spray-on clear coat, photo preservation spray, etc. are all viable options depending on what type of paint you used for the base and top coats. I use a water-based varnish designed for clay, paper, and wood for ALL of my projects (including my first Instructable). It's primary properties include being odorless & quick-drying while working, and waterproof & safe to handle when dry.

Step 5: Centerpiece

The centerpiece for this frame is completely a personal choice and up to you. In my case, I'm fortunate enough to have studied calligraphy; a (not quite yet "lost") art that is beautiful in form, but also functions as a tool of communication.

I chose an Ogden Nash poem about marriage that I found both funny and (viewed from the experience of my 14 years or marriage) sage advice. The font I chose is called Chancery; comparatively easy to pen and one of the more legible fonts used in popular calligraphy. It's pretty clear in the images, but I will write it here for you anyway:
***
To keep your marriage brimming,
With love in the loving cup,
Whenever you're wrong, admit it;
Whenever you're right, shut up.
***

That said, the steps (as illustrated) are:
Step 1
Create the piece.

Step 2
Apply double stick tape to the boarders of the piece, then cut it to size.
(I cut it slightly smaller than the frame size.)

Step 3
Mount the piece onto a background, then cut the background to fit the frame.
(I used red natural fiber paper to match the frame backing in the next step.)

Step 4
If you didn't sign the piece because you thought it would detract from the final product (as I did), write a message and/or sign the back.
(If the frame you prepared for the centerpiece is not double-sided, skip this step and go get a nice card.)

Step 5
Dry-Fit. If it doesn't fit easily now, it won't when you get the hardware put back on either.

Step 6: Backing

The corrugated cardboard backing that came with the wing frames, though functional, is not good enough for a gift.

Step 1: Cut panels from heavy card stock
(second image)
Trace the frame's glass and cut-out a piece of card stock. Since my plan was to cover the panel in leather, I cut it out a little smaller on two sides to accommodate the thickness of the material.

I always have heavy card stock on hand for various projects, but you could potentially use an old cereal box, postcard, paper portion from blister packaging, or even the very same corrugated cardboard as long as the material you choose is sturdy.

Step 2: Affix panels to leather
(third image)
Run a strip of double-stick tape down each of the long sides of the panels. It is not necessary to tape the short sides as the tape is only being used to keep the card in place for the next steps of trimming and gluing.

Tape one end of your leather (or fabric, paper, whatever you decide to use) to the floor and stretch the other side. Making sure the material is stretched before you affix the card stock will ensure no wrinkles when complete.

Step 3: Trim the edges
(fourth image)
Cut the leather about 1.5cm from each edge with a box cutter against a ruler (without cutting yourself or anything else), then trim each corner at a 45-degree angle. This creates 4 "flaps" that will be wrapped around the card stock and affixed with hot glue.

Step 4: Glue the edges
(fifth image)
Starting with the long sides (where double-stick tape was applied earlier), wrap the leather around the card and affix with hot glue (sparingly to avoid bumps and wrinkles and without burning yourself).

Once the long sides are in place, affix each short side by stretching the leather gently, wrapping around the card and gluing as above.

Step 4: Beautify the front (Optional)
(sixth and seventh images)
This step is not essential, as the front of these backing pieces will be covered once photographs have been inserted into the frames. For the sake of presentation, however, I opted to decorate the frames to match the background of the centerpiece.

Cut your decorative paper slightly larger than the overall panel size and apply glue sparingly to the center. Avoiding bumps and wrinkles here is vital; this part will touch the back of any photos inserted into the frame!

Trim the (now attached) paper to align with the edges of the panels (be careful not to cut the leather) and glue into place. When the glue is cool to the touch but not completely set, squeeze out the excess toward the edges and allow to dry. Once dry, the excess can be carefully removed with tweezers.

In the end, the edges of your backing panels don't have to be perfect (since they'll be covered by the frames), but make sure they fit!

Step 7: Assembly

Step 1:
(second image)
Start by attaching your hinges to the wing frames. Always tighten each screw a little at a time alternating between them to make sure the hinge is square and positioned correctly.

Step 2:
(third image)
Place the first wing frame on top of the center frame and align the edges. If the frames are differently sized, align the bottoms to make sure it stands properly.
With the wing frame still resting on the center frame, start and tighten the screws in an alternating pattern as if you were changing a tire.
For example: Imagine the hinges are numbered 1, 2, 3, 4 from left to right.
The order in which they should be tightened would be 1-3-2-4, or 2-4-1-3, etc.

Step 3:
(fourth image)
Repeat the above steps for the other side.

Once the hinges are in place, attach the tabs that hold the photo backings (see next step).

Step 8: Problem-Solving

A problem came up when I went to attach the tabs that hold the photo backing in place.
Though I tried to cover avoidance of potential problems on a step-by-step basis, the one I didn't anticipate was the backing being too thick.

While this is not a serious issue, I wanted to make sure there wasn't too much stress being put on the tabs that hold the backing in place, so the tabs would need to be off-set to accommodate the thicker backing panels.

The solution was to shim the tabs with washers.

Washers could be purchased (if you find something of appropriate size and color), but I had an old piece of rigid black tubing that matched the black plastic tabs perfectly. Careful slicing solved the problem in a matter of minutes.

Refer to the image for the steps taken.

Step 9: All Done!

The project completed, all that's left to do is pack it for the trip to the wedding! I would photograph the packing process, but a printed copy of this Instructable will be included with the gift, so the the laws governing space-time would make that difficult. I'll leave packaging up to you!

Thank you for reading, good luck with this and all your projects, and I hope your gift makes someone happy!