When I changed the tranny fluid a couple weeks ago I drove the rear of the car up onto plastic ramps (these:
http://www.amazon.com/Blitz-11903-Rh.../dp/B000AMMN9O). I then used 2 regular jacks on the left/right front/side jack pads and made it level. Once level, I placed a bottle jack onto the front/center jack pad as a safety in case either of the 2 on the side failed. I also placed some jack stands I had laying around right next to the jack stands on the side for extra safety.
I don't mind getting underneath a lifted car if there is 2 or 3 layers of safety.