I have a walk in closet and most of the fabric is on display. And what is put aside is in clear plastic totes so I can also see that. Most often I buy for stash, and don't care if I buy the same fabric multiple times because I'll eventually use it. Most often when I get an idea for a quilt, I pull from my stash and only purchase for a specific project when I'm already committed to doing it. I do have a few kits I've purchased, but it's easy to keep them stored in the packaging they came in (though they are prewashed and ready to go now.)
Now - if I can get a better handle on embroidery designs and thread. . . at least I buy most from the same online store, and it yells at me if I put something in my cart I've previously purchased (and that happens a lot!)