I don't keep a huge fabric stash but enough to warrant some sort of system of organisation that easily makes me find what I need. I used to fold my fabric and put it in piles according to what I would use it for: heavy fabric for bottoms and jackets, light-weight fabric for tops and dresses.
Neatly folding and piling fabric is not as easy as it sounds and the moment you start rooting for just the right fabric for your next project it all gets messed up again. That's why I have started to roll rather than fold my fabric.
It's easier to store, takes up less space (which is also true when you try packing clothes into a suitcase) and the fabric is less likely to get creases that are difficult to iron out over time.
Any fabric can be rolled easily and piling them on top of each other is less messy and keeps all the fabric in view.
When I roll my fabric I use scarps of leftover fabric from previous projects to tie around the fabric roll and attach a label to it. I cut labels from old pieces of cardboard from cereal boxes or anything I find lying around and note down the type of fabric, the fiber content, the amount I have and whether I have pre-treated or washed the fabric.
This way I don't have to unroll every fabric to find out if I have enough for a project or guess as to whether it's been washed or not.
This system works very well for me and stops my fabric stash from taking over. Do you have a fabric organisation system? Or do you just throw it all in a big old plastic bin and be done with it? What works for you?