Like most, I level front to back with the tongue jack. Then if it is only a "very small" amount I will us the stabilizers. Mostly I have found it useful to tighten the slide side a bit more before I run the slide out to compensate for the extra slide weight. I use the hand crank so I can judge the pressure.
The trouble with the stabilizers is they are not designed for lifting up the trailer weight. They are designed to take a small amount of pressure off of the springs so the trailer does not bounce.
Running up on boards seems to be the common remedy though they do sell some nifty leveling ramps and cams.