You can use creative paper materials, or you can use a plain piece of notebook paper. Make sure that you start with the paper's back side facing up.  Try gold or silver foil paper to make the ring look even more like it’s made out of metal. You can find such foil online or in many craft and even some department stores.  A standard piece of paper at 8 by 11.5 inches will work, although people have made paper rings out of smaller squares, even post-it-notes! Use colored paper if you want to make your ring colorful. Really, though, any piece of paper would work. You could even make a paper ring out of a regular piece of lined notebook paper.  You could also try using special Origami paper, which is the Japanese art of paper folding. Try washi or chiyogami, which comes in different colors and designs. This paper, which can be purchased online, is used to make Origami paper designs. This is the first in what will be a series of folds needed to make the ring.  Cut the paper in half where the fold was. Use the crease where you folded as the guide for where to cut the paper. Take either a pair of scissors or just carefully rip the paper at the crease where you folded it.   You will now have a rectangular piece of paper. Once you’ve cut the piece of paper in half, you should fold the rectangular piece of paper you’re left with in half again. It should now be a smaller rectangular shape. The process of making a paper ring involves a series of folds and unfolds.  After you've unfolded the paper, fold both sides of the paper once again to meet the central line of the paper. Basically, the horizontal end of each folded over side should now meet in the middle. #*Note that the paper is getting smaller and smaller each time you fold it! Now, fold the already folded paper once again, this time completely in half by folding the paper to the right. It will have a square like shape. You are creating the ring through a series of folds. They should meet at the center line.  Think of these folds as creating the tip of a paper airplane. That's how it should look. The end of the paper should now form a triangular point. You’ve got a few more folding steps to go before you have a true paper ring. Be patient! Pull the sides of the paper out, and pop up the top of the folded paper so that it forms the center of the ring. You may want to use a piece of tape or glue at the bottom of the ring to make sure that the ring holds together. Wear the ring or give it to someone you care about! They will most likely appreciate the thought and care you put into it.

Summary:
Choose a single piece of paper. Fold the paper in half horizontally. Fold the remaining rectangle. Unfold the paper again. Keep folding the paper. Fold both of the paper’s edges in. Tuck in the corners. Fold both lines to the center. Glue the ring together. You’re done!