Look on the bright side:
Which level you set the brightness of your screen at will depend on where you're riding. If you'll be in the dark woods all day, a medium to high backlight level will work. In average daylight areas, you can likely get away with a lower backlight level, though you will need to crank it up when the sun starts to drop. Typically, somewhere between 55% and 70% should be fairly visible for most trail rides. Keep in mind that this will draw juice from your batteries, so decide for yourself if you want the backlight to time out after a minute or two or always be on. The same goes for warning tones; who really wants to hear constant beeping over motor noise, anyways?
Constantly adjust your zoom.
In order to maximize the benefits of your GPS display, you'll need to find the best zoom level for the terrain, speed and route that you're riding. In most instances, however, this means constantly adjusting your zoom level to suit what you're doing. For example, if you're buzzing flat out on a fast fire road, you might want to zoom out to between 0.5 or even 1.2 miles. But if you're trying to navigate a set of switchbacks in the woods, you could be in as close as 50 or even 30 feet. This is another one of those things that you'll learn through experience, but there's nothing wrong with continually adjusting your zoom to find the best display for what you're doing at that moment. On average we set our zoom to around 500 feet or less in Romania, but would adjust this as the terrain changed.
Stop before you fidget.
This might be a good time to point out the obvious fact that riding a motorcycle takes exceptional concentration, especially if you're trying to navigate through unfamiliar terrain. While it's OK to glance at your GPS to make sure that you're on course, you should never look at it for extended periods of time; doing so is a sure way to find yourself upside-down in a ditch. If you get lost or just want to tweak a setting, don't try to fidget with your GPS on the fly. Instead, find a safe spot to pull over and do what you need to do. Not only will this make the required action faster because you'll be giving it your full concentration, but you'll undoubtedly be saving yourself from doing something dumb while not watching the trail.
Find higher ground.
Let's be clear: Modern GPS units are incredibly sophisticated, but they aren't magical. If you're not getting a clear satellite signal, it's probably because the antenna isn't finding a good line to the sky. If this happens, spare yourself a freak out and instead put your energy into finding higher ground. There are a lot of things that can affect a GPS signal-from clouds and fog to dense trees or buildings-and nine times out of ten you just need to get away from them to reacquire the satellites.
Double up.
If resources and handlebar real estate permit it, serious off-roaders should strongly consider running two GPS units, side-by-side. The reason for this is that two screens allow you to effectively double your view in that you can run one GPS zoomed in tight and the other backed out. This eliminates the need to play with the zoom level and it also gives you a backup should something happen to one unit or the other.
Secure for safety.
If I rode with $250+ of cash on my handlebar, I'd sure as heck make sure it was secure. Your GPS is no less valuable than money, and whether you use safety wire, a lanyard or a zip-tie (pictured), you should be sure to tether your unit to its mount. In Romania, my teammate lost one of his Garmins in a high-speed crash, and it took a scary 45 seconds for us to find it. Don't make the same mistake.
Carry extra batteries.
Sounds like a no brainer, right? You'd be surprised how many people forget to pack spare GPS batteries in their fanny packs. AAs weigh next to nothing and take up little space, but you need to make sure to store them properly so they don't rattle around, leak or drain. That said, keeping spare batteries on hand (or, better yet, tapping into your bike's power source) will ensure that you aren't left hanging halfway into a ride.
Remove after flight.
After your ride is over and you've expertly navigated your way back to the truck, take a minute to pull the GPS out of its mount and store it in a safe place. If you're an adventure rider, this will keep your GPS from being stolen if you head into a restaurant at the end of the day. For trail warriors, making a habit of stowing your GPS after a ride will ensure that you don't accidentally leave it out in the elements on the trailer ride home or pressure wash it with your bike. I've found that a goggle bag works really well as a place to keep a GPS safe and sound while not in use.
Clean with care.
Despite most GPS units' claims to be 'weather resistant,' you don't want to go blasting your GPS with a garden hose to clean it off-most manufacturers' warranty plans don't cover raw stupidity. Think of your GPS as a delicate cell phone, and care for it as such. This means soft rags, lightly soaked cotton swabs and no harsh chemicals that could eat the rubber or plastic components.
Have (responsible) fun! Riding with a GPS opens a variety of doors for the off-road rider, and is a fun tool to use to help you explore the great outdoors on two-wheels. Have fun feeling like a fighter pilot as you plot your way around your favorite trails!