I always keep a water proof container with TP, matches, flash light, spare plugs in my boat.
I also have a spare prop and flo torque hub kit as well as a spare prop nut and a prop nut wrench in my boat.
I have a small compressor & tire pressure guage I keep in the truck for filling low tires etc.
Also have a 4 way tire wrench along with the original vehicle lug wrench.
On long trips I keep a spare bearing set, grease and tools in the tow vehicle. Don't do many long trips anymore though.
The next one will probably be in 12 years and I retire to Northern BC.
Forgot an important piece of info.
Twice a year I go over my trailer looking for loose brackets, broken bolts, broken welds and broken spring leaves. I've seen what happens when you ignore these things.
There was a guy last year or the year before trailering his big pontoon boat back to town and had a spring break. When it let go it ripped the axle right off the trailer!!!!
Years ago while doing one of my inspections I found a broken weld on one of my spring hangers. If I hadn't noticed I could have ended up in the same predicament.