One of the easiest quilts to make with fat quarter is from the first Turning Twenty book. Twenty fat quarters are cut into squares and rectangles, mixed up, and sewen back together to make interesting combinations. Then the new blocks are turned differntly from it's neighbor and put together block to block. It makes a beautiful quilt and isn't hard to do. I can't remember for sure, but it seems that 25 or 30 FQ make a queen size quilt. And there isn't much waste of fabric.