If you dont have the time to prepare for the trip, then dont go. In extreme environments like Arizona, it can be a life or death decision. You can get in serious trouble for not bringing a very simple item, like water. Other basics include: tow strap, jumper cables, shovel, jack, spare tire--you would be amazed at how many vehicles I have had to rescue for simply not having a suitable jack and spare tire on board. For a more complete list of things you should consider bringing, see the 4-Wheel Drive Guide by Tread Lightly, available on their website--you can even download a PDF copy for free.
Also, research your intended trip route. Not only are there various public land management systems to deal with, but also road conditions can vary widely from year to year. If you are not traveling with someone who is familiar with the trail, at least talk to other four-wheelers ahead of time, and research the trails rating and conditions. Never go alone into remote country, and especially if you are attempting a trail that is going to challenge your capabilities or the capabilities of your vehicle. A good rule of thumb is how far are you willing to walk back? Always leave details about where you are going and when you plan to return. Dont count on someone coming along to rescue you by chance.
If you come across someone who is in trouble, help. Signs of someone in need of assistance include: someone walking along a 4x4 trail, a vehicle parked with the hood up, or someone looking under their vehicle, or waving at you as you approach. If you encounter someone on the trail who is stopped, it is cool to just say Howdy, how yall doing today? If you see a parked vehicle and no occupants, someone is on foot nearby, either intentionally or unintentionally, so be alert. Offer to call someone for them. If the vehicle requires towing, do so only if you are willing, able, and the vehicle has proper recovery points. Learn first aid and CPR.
If you drive by someone on a dry dirt road at 10 mph or more, you are DUSTING them. Many 4x4s are open-air, so a big cloud of dust is not just inconvenient, but hazardous if the drivers eyesight or breathing is momentarily impaired. Be considerate and mindful of what your actions cause.
Always allow each vehicle to traverse the tougher obstacles one-at-a-time. Closely following another vehicle is dangerous in any situation. In off-pavement driving, braking distances and maneuvering is significantly affected. Keep distances of at least thirty feet between vehicles. This allows vehicles room to brake and maneuver, as well as sufficient distance to read the terrain and pick a line. On steep four-wheeling hills, downhill vehicles could be struck by debris flung from spinning tires, or worse, a rolling vehicle. All of us have experienced failed climbs. You do not want to be tailgating someone up a hill when he fails his climb.
Another good reason to wait for other vehicles to finish traversing an obstacle: I have seen multiple vehicles get stuck simultaneously in the same mud hole. I am sure the guy in the last 4x4 wished he had watched the other guys go all the way through first. Sorry, but that was hilarious! You might be a redneck if... No offense intended to rednecks, as I come from a proud line of them.
Passing involves getting by each other, either in nose-to-nose situations or when one driver wants to proceed more quickly than another. As with dusting and tailgating, above, passing on the trail requires a sense of safety. If someone obviously wants to go faster than I do, I find a wide spot and pull over to let them by. Always look for a place wide enough so that neither vehicle will have to drive over vegetation or lean into each other. I have seen four-wheelers scrape each others roofs as they tried to get by each other in a V-ditch. Remember, four-wheeling is three-dimensional.
When you come nose to nose with someone on a one-track trail, whoever has a wide spot behind them backs up. But, safety dictates that if you are on a hill, the vehicle driving uphill has the right-of-way. This is because backing down uneven terrain poses the problem of poor visibility, with the driver potentially backing down a ledge off-camber and rolling.
Once I encountered a driver who was very considerate of other vehicles, but in his eagerness to get out of the way, he drove over live shrubs, and high-centered on a rock. Please do not drive over shrubs or off the trail. In most cases, it will only take about three seconds of calm analysis for both drivers to quickly find an easy route. In tricky situations, it is not a bad idea to get out and discuss the best way to proceed, or have a knowledgeable passenger spot for you.

