If I'm on a shop hop and don't particularly love anything, I'll at least buy a 1/4 yard. If I like it, I'll buy 1-2 yards. If I LOVE it, I'll buy the rest of or the whole bolt. Once I bought 16 yards! Absolutely loved the fabric!!!
If I have any leftovers (which I always do), I'll cut them into 2 1/2" strips and eventually use them in something. Whether it be a scrappy log cabin or whatever I make.