Set yourself some personal guidelines and budgetary restriction. Maybe, I won't buy any more fabric until I complete a couple tops using my stash. Or, I'll buy only one new yard and see how I can combine it with my existing stash. Mostly, I just immediately delete the fabric websites from my computer. Don't even open them. Maybe you could trade some of your stash with another quilter of similar taste. It would be new fabric to both of you and no $$ changed hands. For me, finding fabric is kind of the thrill of the hunt. Once I buy it, pat it a couple of times and incorporate it into my stash, there it remains and I feel let down.