On of the most important things to remeber is to keep your RV's and vehicles in the safest condition possible. This can sometimes be over looked. I guess, from past expeirence, too focused on planning for the trip itself.
How many times have you seen a RV, boat, ect. left along the roadside with only one wheel or up on jacks? More than likefully one of two things have happened, blown out tire and no spare tire or, the wheel bearings went bad.The bearings should be repacked on most trailers atleast every 1000 miles.
Make sure to follow your manufacturers instructions carefully on routine maintenance on all equiptment.
Don't forget to check all of your lights and make sure they are working properly and have spares on hand, just in case.