My stash is composed of fabric left over from projects I've done with a few estate finds and 'gotta have it' pieces. It's not a huge stash. I think I always choose a pattern first. Then I go to my stash to see if anything will work. Most of the time the amount of fabric I have isn't large enough for a full quilt so I either have to start thinking of ways to use that up or take a trip to the LQS. It works for me.
Right now I'm making 2 twin sized quilts from my UFO pile. The blocks were from a class I did years ago and most of the fabric for sashing and borders came from my stash. I only had to buy a couple more coordinating fabrics and it will come together nicely. I'll have 2 quilts for very little $$$ outlay...... Again, works for me!!