I love a quick, easy project that cost less than $20 and can be done in under an hour! These hanging circles are made from embroidery hoops that can be purchased new for between .50 cents and $2.00 a piece. Or if you want to be really thrifty, you can often find them at second hand stores for around .10 cents a piece!
My inspiration for these came from something like this. For my own variation I spent around $5.00 for the embroidery hoops and used left over spray paint. If you don't have any spray paint lying around that you'd want to use, it would really only take around 3 cans, depending on how many different colors you want to use.
I didn't make these circles adhesive because I didn't want to damage my walls with tape. These are hung with tiny nails, and can easily be rearranged if the mood hits me. Although, I didn't make any solid circles, but I'm sure with a little ingenuity and creativity you could easily come up with a way to do that!