I bolted a 2" ball onto an old jack stand and use it anytime I disconnect from the TV. Very stable and easier than pulling jacks down from the front frame. Crank up on the tongue jack and then back down on the jack stand and you're done. I leave the tongue jack down with the wheel touching the ground as an added safety measure. The jack stand sits on a board for extra stability in unpaved areas. I have two standard Atwood jacks on the rear frame.
I use jack stands forward and aft as needed. Here in Fl. everything is pretty flat so I will leave the swingaway jack down on the front and adjust the regular jack in the rear to level. If I ever go the a mountainious area I might change things some though.
We use two Atwood sliding jacks at the back corners and the crank dolly wheel at the front. I drop the front to level plus about an inch. Lower the rear jacks and then crank up the front to level. Puts just enough weight on the rear jacks to keep the trailer from wobbling.