How can one have too many fat quarters?
If you are stuck, pull out a color wheel and choose a color scheme. Then go to your FQ stash and sort out the colors you need. Pull a variety of values of each color. Then get cutting.....
If you have lots of different colors maybe a twister quilt would be fun. You need some contrast between squares when you make it.
For those-" why did I buy it FQs" cut them up for a block that has some small pieces.... It's amazing how uglies plus a solid (red, black, etc) can make stunning quilts.