Here's a rug I just finished. I found the pattern in book of knitting in the round patterns. It was rather mindless, but that's what I wanted. Just a simple round pattern adding stitches in four locations.
I added a crocheted border to finish it off. I forget to add stitches as I was crocheting so it started to curl, but being pure wool I blocked it and it came out flat. Doesn't really hold a circle well. You have to put it on the floor and sort or shape it. Then it'll stay in place.
A great way to use up some extra yarn. You just keep going around until you run out or you have the size you want.