You can make a decorative hairpin VERY cheaply with items you already have at home. (If you don't have any straws, a quick trip through the nearest drive-through can remedy that!)

As requested by MANY comments, the last step is a video to explain it a little clearer!

Step 1: What You'll Need:

You will need:

•2 plastic drinking straws
•a bobby pin
•scissors

Step 2: Flatten Your Straws

Do it. Now.

(It's easiest if you stretch it along the edge of a table or a book at an angle and rub back and forth.) The flatter your straws are, the flatter your heart will be; It will also make the weaving a little easier.

Step 3: Begin Folding

For illustrative purposes, the white straw is straw #1 and the pink straw is straw #2... Because I said so.

1)Fold straw #1 in half and angle it to form a "V" then slide straw #2 into the bottom of the "V" shape.
2)Fold the right end of straw #2 up in FRONT the right side of straw #1 so that it is parallel with the left end of straw #1.
3)Fold the right end of straw #1 around the FRONT of the right end of straw #2 and tuck it BEHIND the left end of straw#1.
4)Take the right end of straw #2 and fold it over the FRONT of straw #1 and tuck it BEHIND the left end of straw #2.
5)Take the right end of straw #1 and fold it BEHIND the left end of straw #1, then bring it in FRONT of the right end of straw #2. (It should now be parallel with the left end of straw #2.)
6)Fold the right end of straw #1 BEHIND the right end of straw #2 and tuck it in FRONT of the left end of straw #2.
7)Fold the right end of straw #2 in FRONT of straw #1 and tuck it BEHIND the left end of straw #2. Then fold the right end of straw #1 over the FRONT of both ends of straw #2 and BEHIND the left end of straw #1.
8)Bend both sides of straw #2 down so that the longer end will lie down flat over the middle of the heart.
9)Tuck this longer end under the cross section of straw #2 that runs straight through the middle of the heart.
10)Pull this end through the cross section tightly.

Step 4: Make It LOOK Like a Heart!

Trim the edges of each straw end so that they are flush with the sections of straw that are overlapping them. (You'll need to trim the two edges sticking out at the top, the edge sticking out underneath the cross section and the edge sticking out under the piece that is tucked under the cross section...This is detailed in the 3rd photo here.)

Step 5: Attach Pin

The side with all the trimmed edges is the back. This is the side to which we'll attach the bobby pin. Slide the top part (the side with the zig-zag shape) of the bobby pin under the piece that is tucked through the cross section. (Be careful not to snag your trimmed end of straw here.) Now carefully push the bobby pin through the cross section...And VOILA!!!

Step 6: Enjoy!

Now fix your hair up nice (at least nicer than mine) and find a nice straw-coordinating outfit!

(The second photo is one made from two of the pink straws that McDonald's has to celebrate their new berry smoothies... Oh, and Dunkin' Donuts also has cute orange straws with pink stripes!!)