Expedition Portal has posted a short piece outlining some off-road tips for beginners. It's good advice. I listed their 5 suggestions below with some comments.
I hardly ever air down my tires. Mostly because my LR4 has 19" wheels and my previous LR3 had 18" wheels. In both cases, that leaves little sidewall to flex and too much flex is undesirable since it can lead to tire damage or maybe break the bead. Airing down the tires will increase the amount of flex so I just leave it alone.
Pick a Proper Line
This is an obviously important tip. It helps to know where you have the most and least ground clearance on your undercarriage., then you have more options to pick a line that clears the boulders. Many of the trails I drive are very very remote, and it's a good idea to take simple steps to reduce the chances of any damage. That means picking the safest line. Mostly, this is about choosing the path along the trail that poses the lowest threat to your tires or undercarriage. But it also means avoiding damage to the body. Sometimes I need to take a more risky line on the trail, to avoid scraping a huge boulder (6 ft tall or larger) beside the trail, or avoid a tree that skirts the trail, or avoid a very loose edge on a shelf road. I'm not above moving a few boulders to improve my path. I don't go overboard and make it smooth, after all, I'm there to drive that challenging trail.
Use a Spotter
I've used spotters many times. Mostly on the very difficult trails in my area, such as Mengel Pass (the "rock garden" section: video I found on youtube), Shuteye Peak trail (video I found on youtube), Phillips Loop trail in the Calico Mountains (video I found on youtube). Modified rigs don't need spotters on those trails. My Land Rover has less ground clearance, and it's my daily driver, so I'm extra careful when I can be. I've learned that mechanical engineers make excellent spotters. They seem to have an intuitive understanding of 3 key things: (1) how vehicle suspensions work: the articulation, dynamics, damping, etc., (2) that the undercarriage is not flat and offers some lines with much more ground clearance, and (3) that the rear tires don't follow the same line as the front tires.
Maintain Appropriate Speed
This mostly affects me when I'm crossing deep sand or crossing rivers. There are no set rules because conditions vary (even at the same location over different times of the year). Experience is the best instructor. When I'm not sure about a given situation, I start with decent speed and momentum, paying close attention to the vehicle performance (deceleration, traction, bow waves, etc.) so I can quickly either speed up or slow down.
Know When to Turn Around
This is an excellent tip and is often not covered in the trail books on the market. I turn around a lot. I go off-roading often, but post blog entries for a fraction of those trips. I don't like posting about my "failures." But I don't mind turning around. Seriously. I enjoy the trip even if I turn around. The most common reasons for me turning around are: washed out road, closed trail (BLM and NPS have been closing many old trails across the Mojave desert), way too difficult trail to tackle alone, weather change has made the trail more dangerous than I'm comfortable with (rain storms in the backcountry of Utah), and running out of time (I want to get to my destination camp site before dark). I normally identify alternate routes in advance that I can take if I decide to turn around.
Here are a few of my own tips to add to their list:
Know the Area
I enjoy knowing about the area I'm driving through; it's history, geologic features, etc. It's easy to learn about a trail in advance. If it's used by others, then there's bound to be something on the internet. I also look up the names of features in the area shown on my maps. That's a good way to learn of nearby sites to visit. If this is new to you, then you might target your research on these sorts of things: trail difficulty, alternative routes, history, nearby places to visit/explore (historical sites, scenic view points, strange things seen in satellite imagery), cell coverage, dangerous animals (rattlesnakes, mountain lions, bears, honey badgers), weather patterns, etc. The popular trail books include this kind of information for the trails they describe.
Bring the Gear You Never Want to Use
A little preparation can make the difference between a miserable trip and an adventure. I'm a fan of bringing all the gear (or at least a lot of it) that you never want to use. Here's a list of the things I can think of now. I bring all these items on my adventures. Even on simple day trips.
- extra water (for you, your passengers, your pets, your radiator)
- shovel, axe or hatchet, saw, tools
- extra spare tire
- work gloves (bring extra so you can recruit helpers when you're changing a tire)
- large base for jack (for soft, muddy, sandy, gravel surfaces)
- tarp or other ground cover (great for shade or shelter, but I lay it on the ground when I need to crawl under my truck to clear brush or fix something)
- outer clothing, hand warmers (the weather can change)
- bedroll / tent, space blanket, lamps/lanterns (you may need to spend the night)
- hiking gear (you may need to hike to the nearest cell coverage in an emergency)
- air compressor (2, if they're cheap units that overheat before filling an SUV's tire)
- tire repair kit
- traction aids, tow strap or snatch strap, shackles (assume you'll get stuck)
- gps, maps
- cash (you may need to compensate some stranger for helping you)
- medications (you may need to spend the night)
- jump starter
- extra fuel
Here's a trick: put many of those things into a single 14-20 gallon plastic bin. Then you only need to load that bin and a few other things into the back of your car before you head out. I've been doing this for years and it's super easy.