While special square-shape origami paper is the usual material for paper folding, it's possible to make origami shapes out of bills--usually dollar bills--as well. Because the paper you're using is a long rectangle instead of a square, there's a different range of typical shapes made from dollar bills instead of origami paper. Using a crisp dollar bill will make the ring tidier and nicer looking, but you can use just about any dollar bill--or any denomination--out of your wallet.
Lay your dollar bill face up. Fold the white margins inward along both the top and the bottom of the bill.
Bring the folded bottom edge of the bill up to the top edge and crease. Then bring the newly folded bottom edge up to the top edge again and crease once more.
Fold the white margin on the right side of the bill in and crease. Then make another fold on that side--of about 3/4 inch--so that the numeral "1" shows clearly. Fold the left edge of the folded bill underneath, to the middle of the letter "O" in "ONE" as printed in the middle of the dollar bill, and crease.
Turn the bill over and pinch the last fold made. Bring the folded end down at a right angle and crease.
Flip the bill over again, so that the right-angle fold you just made is against your finger. Wrap the folded bill around your finger.
Bring the folded edge of the bill that protrudes at right angles in over the ring shape you just folded.
Tuck the edge of the bill around the ring band and tuck it into the triangle-shaped flap inside the ring band, as seen in the photo.
Shape the heart out of the leftover, protruding piece of the bill. Tuck the corner of the folded edge in toward the middle.
Fold the pointy corners in to make a dull point at the end of the protruding bill.
Squash fold the protruding part of the bill--that is, bring the entire thing up and over to the left and open along the middle crease--to reveal the heart shape on your dollar bill ring.