I use a small 3 ring binder (about 7" X 9", I think) and you can get plastic sleeves that size at Hobby Lobby or scrapbook places. I keep a photo copy of the pattern and yardage requirements in there, and take it with me when I shop. If I buy one fabric for a quilt at one place, I cut a small swatch to put in the sleeve...until I get all the pieces I need.
I started this because our state shop hop handed out these small binders one year....I ended up putting the info I needed in it when I went "hopping"...and the idea worked so I just kept up with it.
I also keep a larger binder with quilt ideas out of magazines too. But the ones that I am planning on working on soon, go in the small one so I can take it with me.