I have managed to sort my fabric in several sections;
Future quilts; I keep a pile of fabric for future quilts because I don't always have all the fabric at once, so I buy as I have money and eventually end up with enough to make that particular quilt. I have at least 7 future quilts.
Kids prints in one pile, with smaller pieces on top. All folded neatly. All my fabric is piled vertically since I never got to make those cards to store them horizontally.
Whites, creams, beiges
Dark prints
Light prints
Florals
Plaids
baskets for scraps; reds/oranges, blues/purples, blacks, whites/beige, greens, browns.
And it is all stacked neatly on my 4'x7' wooden bookcase my husband made specifically for my fabric. I don't know exactly how I came to this sorting, but it works for me. I know every fabric I have because I ironed, folded, stacked and sorted all of it. At one time, I even reorganized it because something just didn't look right. I also have a whole other shelf for blends. That's a must since I won't put any of those in my quilts. I usually reserve that fabric for making new doggie beds or something the kids want. And I keep all my clippings and stuff it into a plastic bag so I can save for a new doggie bed. Why throw it out if I can use it there.
I really don't know if there is any one system that suits every quilter out there. We each have our own needs and what works for me may seem completely unorganized to someone else.