Pick a site that is level or tilts away from the deck. You do not want to have blocks under the deck side tires to level. If you do, the camper will lean into the deck as you pull you away.
Pick a site that allows straight in and out of the trailer and TV, this will greatly reduce the likelihood that you'll swing the trailer into the deck.
Make sure the deck is low enough to clear the steps, theses are things most often damaged. Leave a gap of 6 to 8" between deck and wheels.
build stairs out of decking that you slide against the camper and then away when ready to move.