I agree with the stands / supports, just not in the way 22george uses them. I've got a pair of "tall" tripod style ones on a jack screw rather than teeth like a traditional jack stand. I think mine are Torin Big Red. You put the car up to where you want, let it down to the next safety latch, and then put one stand at the front and one at the back. Spin them up until they touch for added stability.
I really only use them with longer vehicles like my truck, but depends what I'm doing. With a longer vehicle if you're wrenching at one end or the other, it tends to rock quite a bit. The support stands take away that rocking.
Also like someone else said, oil drain pan with the extending neck. I spent my first couple oil changes holding a drain pan in my hands trying not to get splashed. They make ones with smaller buckets than the huge pro ones that don't cost too much.
I'd also say a good work / trouble light if you don't already have one. With a car up in the air, no matter how good your shop lighting is, the bottom side is still dark. I upgraded to the DeWalt 20V tripod light, which is great under the lift. You can point it up and light up the whole underbody.