I agree with the vent covers and X-chocks.
We also like a good awning mat - One that lets water through.
Not as sexy as an awning mat, but a decent multimeter and a variety of tools, Dicor caulk, and fuses for those inevitable fixit jobs you will need to do while camping.
A pad and pen for those first few trips. If you're like me, you'll find quite a few items that you'll want (and some that you'll need) once you get out a bit.
DW, 3 Kids and our Goldens
2012 Shamrock 233S
2008 Toyota Sequoia 5.7L 4WD