My usual cut is 1 yard. If I'm pretty sure I will want to use the fabric as a border, I buy 3 yards. The only time I buy more yardage than that is if I want to use the fabric for a backing. (I should mention that I buy almost all my fabric when it is on sale at a local fabric outlet, which means batiks are about $7 a yard. When I need a lot of yardage for muslin, applique background, etc. I usually purchase that from either fabric.com or from Hancock's of Paducah when they have their annual sale. I don't buy much fabric at $12/yard!)
The 1 yard cuts of batiks I have are becoming a nice stash, plus they fold nicely for storage by color.
I have found over time that I really don't care much for fat quarters. If I love the fabric, it's not enough and I am afraid of using it all up by cutting into it. If I don't love the fabric, it sits around way too long because it doesn't suit any of my projects. The 1-yard cuts work well for me because I have enough of the fabric that I'm not afraid to use it, but I don't end up with yards of it 10 years later (and I have some of that) after my taste in fabric has changed.