I am involved in a group charity project. It is a scrappy type quilt, and the only stipulations was the 12" block size. What a fun way to reacquaint myself with my horrendously large scrap stash.
I did these three blocks:
"Oh Susanna" Quilt Block:
"Double Pinwheel" Block:
I got all these patterns for free from the McCalls Quilt Block site. There are tons of them to choose from! You could very easily do a sampler quilt or two, or three or four... you get the idea. Most of the quilt block patterns have variations for different sized blocks,too.