What to bring?

Extra socks/Underwear, you never know when they close the road for accident or weather.
Some canned goods/something that doesn’t spoil easy to have just incase, (winter is right around corner)
Few wrenches(9/16,3/8,7/16,5/16 flat and phillip screw driver, tape, zip ties.) such is that, may see an airline rubbing you can zip tie, save problems down the road.
Windex(even though you got washer fluid.) Hammer.
If you’re doing van then a pin is helpful,



Always keep a jacket in truck, you may forget yours at home.

 

Truckers atlas don't blindly follow the GPS all the time. Unless you're dedicated and going to the same places over and over. Flip flops for shower shoes.

 

bottle or two of water
space blanket, painful I know, but awesome if you get caught out on a cold night

 

White sheet if you come upon a accident.
Cash and a Credit Card.

 

Chapstick

 

Flip-flops if you need to shower at a truckstop.
Oops, I see @Boondock already posted that, but I'll leave it anyway.

 

I always carried a paper Rand McNally Motor Carrier Road Atlas, 5th wheel pin puller (preferably the steel ones with a solid handle that can be used as a light hammer), fuses, gloves, window cleaner, notepad/pen (smartphone), sunglasses, rain coat, flashlight. I always got at least one spare headlight for the truck form the shop and windshield washer fluid and gallon of oil. I also carried at least 2 glad-hand seals. You'll probably want a phone holder and charger.

It's cheaper and better to buy the fuses at walmart where you can buy a box of 5-10 fuses of each amperage (5, 10, 15, 20, 30) for about $2 each than pay $10 at the truck stop for a single box with one fuse of each amperage.