There are places to put all your bolts in the back cubby. Ignore those and get a small ziplock. If you ever need to get to your jack they will fall out otherwise.
Get a locking lug for your spare tire.
Get a floor liner (weather tech, or quadratic style)
NEVER take you hand off the door after you remove the retaining strap. Otherwise you will learn what you cowl is. After your mirror puts a dent in it.
REMOVE THE SEAT BELT CHIME
I also like the option that unlocks all the doors with on press on the key fob.
PAINT MUFFLER AND EXAUST
I recommend spray painting the exhaust and muffler if its still shinny. It will likely flake off some and need retouching in small spots over time, but adds a layer against rust. Mine now looks brown and rusted with baked on mud, but a can rub that off and still see the black paint underneath.
I took a red scotch brite sanding pad and sanded real quick it all. Some 100 grit sand paper would be about the same. Or you could just spray and have more chipping. I used rust oleum high heat ultra rattle can spray. It has a grill pictured on the can. Normal spray paint will bake off. I also hit up small bare spots that the factory missed. I would leave the driveline bare so the service dept. cannot say it caused any type of vibration. Getting a can of Rustoleum Rust reformer is a good idea too. If you see any areas with rust hit it with a spray of that. You'll want it after you put scrapes on your skid plates.
I did a thread on extending the breathers. It's a good idea before off roading through water.
If your doing any serious off roading then go with someone and get a recovery snatch strap. A toe strap (that look identical in most cases) or chain isn't a great idea.
Dont drive in 4WD on pavement unless its very wet or slippery. Look up Part time vs Full time 4wd for more explanation.
Going through small puddles (6"+) at high speed can hydrolock you engine with the splashes. If that's your thing you should get a snorkel.
Dont yank it into 4wd. Try to use firm constant pressure. There is a plastic 50 cent part that will pop off if you use too much force. It's there to protect the t-case, but will leave you stranded if you don't know how to fix it. I'll try to find an informative link when I get to a computer.
Get mud off ASAP. A sprinkler is a good way to get the stuff underneath.