This is something that might be considered halfway between Dara and my specialties. I make armor. Dara makes crafts.
This is a cheap way to use crafts to make faux-metal pieces. I have used these methods to make armor that looks like real, decorated armor pieces, but is amazingly cheap and can be made at home with bare instruments for halloween, theater, or cosplay.
Things you'll need:
Knife/scissors, iron, hole-punch, paint brush
Paint, glitter, beads, other decorative items.
Jewelry is the main focus of this Instructable, but you can use the knowledge for crafting lightweight armor as well.
Step 1: Create the Design
Some thick paper would work best for this step. You can also find designs for this online or at craft stores.
Heck, if you're pretty good at tracing or free-hand drawing, you can create your own. Celtic knot designs work well for most jewelry or medallions. Dara likes to make 2 patterns, a blank cutting pattern for the bigger pieces and a clear marking or drawing pattern for jewelry she has to do multiple times. This works especially well for multiples.
Step 2: Trace/Cut Out Pieces
After you have the design, choosing how to use your foam is the next step. There are a few options to manage this step:
Iron on a metallic fabric to the craft foam.
Find metallic-shaded craft foam.
Choose generic craft foam, then spray paint it later. (This is the cheapest)
After you've chosen your method, cut out the design you've come up with. If it's one piece, you can use a soldering iron with a flat face to press in the foam to make it look overlapped.
Step 3: Decorating/Shaping
You think you had plenty of options in the last step? Here's more!
If you ironed on the fabric or chose an already metallic-looking foam, all you need to do is add paint to make it look older or burnished. If you just plan on painting everything that will come here in a bit.
You have the main form of it already, but to make it look crafted, you'll have to do some hand work. Iron over all the craft foam you're working on, and press down the sides to make it look like it was hammered or welded or ground into the shape you want.
Once you have that done, glue all your parts together (if there are any).
To make it look older, you'll need to paint it one way or another. Joints, recesses, edges, sharp curves, all could use a little dark paint that matches whatever metal you chose to make it look like. (Dark gray paint for silver metal, dark orange with a hint of green paint for bronze/coppery metals, bronzeish paint for gold, etc). If you want to make it look FANTASTIC, or just from fantasy, a few well-placed bits of decorative glitter help.
Step 4: Fasteners
Whether you use clips, grommets, eyelets, etc. You'll need to add metal bits to use what you've created. Eyelets/grommets are usually the easiest way. Pick a metal that matches the color you're going for. This allows you to put string, chain, leather, etc through what you've created so that you can wear it.
Or velcro, you never know.
Step 5: Finish!
To finish your product, spray a matte-finish polyurethane finish coat over it. This will help keep the colors from staining and will seal in any paint, glitter, fingerprints, from weathering away during use.
Now that you've finished your piece, you've finished your piece! Let it dry for a bit and you'll be done!