First of all you can setup in some pretty nasty situations if need be, although I will pass on those if given a chance.
First and foremost with most modern trailers they need to be leveled side to side first. I usually use 2x10 blocks for initial leveling and if need be use the lego blocks to fine tune.
I then level front to rear using the hitch jack.
I use the 2x10 blocks and lego blocks under the stabilizers, I don't want them fully extended as they are more stable when partially extended.
Fine tune with a bubble level on the floor and also in the refrigerator.
DON'T FORGET TO CHOCK THE WHEELS. :*)