Anderson Leveler & Jump Starter/Compressor
I use an Anderson leveler for small leveling jobs. It also lifts one tire off the ground if you need to change a tire.
I bought a Jump Starter/Compressor at Costco for about $80. It will pump up a tire without being plugged in, and it jumps much faster than cables.
Keep reading this forum, and you'll find enough modifications to keep you busy for months. I've had mine for 18 months, and I'm still working on it.
I upgraded my tires to a heavier load range and higher speed rating. 65 mph rated trailer tires just don't cut it. The trailer manufacturers put on tires that barely handle the load empty. When you load your trailer with all the gear you want for your trip, you will probably be over the tire rating. I found tires that are rated for 81 mph at etrailer and put them on all of my trailers. Before that, I averaged two blowouts a year, sometimes on the same trip. I carry two spares.
I highly recommend the GEO method for sewage treatment. TST from Walmart is also effective for odor control.
Look into adding solar panels if you boondock. Even if you don't boondock, a small 15 or 20 watt panel will keep your batteries charged up all of the time without plugging the trailer in.
2009 Roo 21ss + 2007 Superduty 6.0