I keep a small tool bag in the back. Basic wrench/sockets, wire cutters, nut driver for hose clamps and a couple of screw drivers. A couple of lengths of 14g wire with alligator clips and a couple lengths of 12g & 14g wire along with variable cotter pins. Couple feet of fuel line. Glove box has assortment of fuses, flash light, gloves, electrical and duct tape. Keep an extra qt of power steering fluid and oil tucked behind the rear quarter panels. Fire extinguisher strapped to cage and a gallon of water in a antifreeze jug. Jumper cables under front passenger seat. Of coarse a jack and lug wrench.
In 34 years never needed more than this for "road trips" and I put a LOT of miles on my Bronco both street and trail. Note that this list is for road trips and what I keep in my Bronco driving daily.
I am extremely diligent in maintaining my truck, do all the work myself and in 34 years have not had to be towed. Odds are it will happen, just hasn't happened yet. Just lucky I guess.
Can not say this any better!
Best advice I've seen in a while!