what dirtydog said.

Buy a jack stand well beyond the weight you ever plan on placing on it.

I use the large crossmember in the front for the jack as well as the stands. I know the stands are kind of close together in that situation, but the control arms are on too much of an angle for me. You could also put them on the frame behind the front wheels I believe.

NEVER get under the vehicle when its only supported by the jack, always put a jack stand under it. And definitely give it a good shake like dirty said again.

Chalk the opposite set of wheels from what you're lifting, unless you trust the park pin/leaving it in gear.

I've had 2 things come off the jack while I was working on them, one was a tractor (poor equipment at a place I used to work) and the other was a high clearance sprayer (the jack sunk into the ground).

 

even jack stands can trap you under a vehicle if they are not on solid ground. I always place a 16" piece of 2x12 under the jackstand if not on concrete and even on concrete lately since had jack stand slide on the concrete and give me a too close for comfort movement from the truck taking it down from the stands...

 

I don't see it being much more work using the spare tire. It allows you to check the spare at the same time. Its not like you need to put all the nuts on the spare. I just use the floor jack and jack stand at a time. I wish they would use the street rims for the spare tire so they could be rotated into the mix too.