Here are some:
--don't confuse going out or even trail runs with the sport of rock crawling. Crawling over rocks and ledges on some trails is not the same as the sport of driving trails that are essentially obstacle courses or choosing the hardest lines elsewhere for the heck of it. There can be overlap, but it is rare, it is usually different rigs, different setups, different compromises, etc.
--don't confuse the lower 48 with Australia. You can overland all you want but you don't have to overland to get anywhere (1-2 nights remote camping is not really overlanding). You can carry all you want but there is no need to. The Australians don't have this choice.
--Travel light: less likely to break something, less need for suspension upgrades, better sand performance, fewer performance issues on road. Seems especially appropriate for 5th generations due to being V6 only. People who want an Australian style overlanding rig should consider the GX 470, 460, or the 200 series. Just sayin' as lots of complaints could have been easily avoided that way.
--Read the 4Wheeler Bible by Jim Allen. It is not recent any more but still covers all the basics. A lot better than watching random youtube videos.
--Use 4x4 trail guides. They also have useful intros with all that you actually need. Watch out for "scratch" or "pinstripping" in trail descriptions if you have good paint. Chances are that "likely brush" in a description published 5 years ago is guaranteed pain nowadays.
--Use good judgment before modding. The aftermarket industry makes lots of claims about lots of things. That's how they make money. About the one thing that is beyond dispute is that the stock tires are inadequate...beyond that...it all depends on goals and frequency of use and also on the generation and the trim. Also, the greater the hassle to get out, the less one will get out.
--Use good judgment on trail. If you are not sure and no one with more experience is with you, turn back.
--Remember that weather can change trails dramatically, especially in the desert. Also, don't be in a wash during or after rains.
--Avoid popular trails on weekends, especially if not yet pinstripped and/or scratched and/or if the traffic is UTV/ATV traffic.
--If solo, let someone you trust, ideally with some idea about offroading, know where you are going, your route, and your cutoff time. If it is a really remote area, do not improvise, stay the route. MUCH better: have a two-way satellite messenger and have a friend make sure their phone is on while you are away. Be nice and send an "all OK" message as soon as back on pavement/in cell range.
--If you are on a rock crawling trail, you know your stuff. If you are not a crawler and you are driving a hybrid trail, remove any rocks you have needed to stack. It is bad etiquette to make that kind of trail easier.
--By the same token, it is okay to improve a difficult overlanding trail that is driven for scenery/camping.
--Established bypasses are fine, but DO NOT LEAVE THE TRAIL and DO NOT DRIVE CROSSCOUNTRY except in the few areas where this is allowed. Don't be the person driving over alpine flowers.
--While it is the general rule that uphill traffic has the right of way, bigger groups also have the right of way and sometimes it is much more sensible for uphill traffic to back up than for the descending vehicle to do so.