There are so many endless things you can do with them!
Make a pattern or get something round that you can trace around. You can make the circle any size you want, but remember the yo-yo will end up about half the size as the original circle. Use your pattern to draw a circle directly on the fabric and cut it out.
Take a needle and thread and fold the fabric towards the center as you sew around the edge. The picture is pretty self explanatory.
Pull the tread as tight as you can until it all gathers together.
and you have yourself an nice, cute, super easy yo-yo!