To phrase it a bit differently:
1) use a level to determine whether the left or right side is low and by about how much (1/2 a bubble, bubble gone, etc.)
2) place blocks (composition, brand are users' choices) ahead of the low side tires.
3) drive the TT onto the blocks
4) recheck left-to-right level
5) if OK, go to step 7
6) if not level left-to-right, back off the blocks, adjust and go back to step 3.
7) set checks to keep the TT from rolling
8) disconnect from the tow
9) level front-to-back using the tongue jack
10) deploy stablizers
11) light fridge and set up the rest of the camp site
TT 2015 19RD "TheJayco"
TV 2003 F-350 "Montblanc" - Housebroken chore truck
Sitting in The Cheap Seats.
And proud of it!