Covering all the windows, vents and skylights.
Parking the RV in reference to the setting sun when it is the hottest. If at all possible nose into the setting sun so the sun is not beating on the 'whole side' of your RV for several hours at a time. Or if you can't then turn the RV around so the awning side is facing the afternoon sun and put awning out and lower to lowest position to block the sun.
All these things DO reduce the temp inside your RV by sometimes 20 degrees.
These are important things to consider when parking in hot and humid regions. Makes a BIG difference how hard your AC has to work.