Mostly 2 yards. There are some things like tonals that I only buy 1 or 1.5 yards of, and some others that I'll buy 2 yards of.
Then there are the "end of the bolt sales" where I get 30% off for buying the end (so yeah - I wander around the LQS looking ONLY for skinny bolts) and I'll buy whatever is there!! And the sales here on QB too - if I like it I buy it.