I bought 3x5 index cards and took them to FedEx Kinkos and had them use the large guillotine paper cutter to cut into 1/4 or even 1/8 sizes.
I use comic book backing boards to wrap my fabric on and put a printed return (the small label) address label. My labels are printed with the following info:
FQ / F8 / HALF
Yd_______ In______
I place one of these labels on the cut piece of index card and circle or write in the size of fabric. I tape that piece of index card to the edge of the backing board. so when I'm looking for fabric for a project I can see if I have enough to complete that project before getting my heart set on fabric only to discover half way through that I don't have enough to complete it.
Here is a picture of mine