I keep a binder of everything quilting. It's a quilt planner, an idea book, my shopping lists, anything and everything to do with our quilting addiction.
A quilt is in the book from conception to finish. I've got quilts that haven't even been started, quilts that are half way finished waiting for more inspiration, swatches of fabric for the quilt.
It's really handy when you live 50 miles from the closest shop and you happen on a LQS. We have an old Bernina bag that stays by the door and when we leave to go off somewhere it gets thrown in the Jeep. It really helps keep you on track.