Boondocking.
This is crawling through trees and terrain while you pick lines and work your way through areas where you just can't rely on the throttle because of the obstacles. The key here is to keep your momentum moving forward at all times on as consistent a basis and as fast-paced as possible.
Boondocking is the combination of movement and lines. If you move too fast, you can get out of position to make the turns or leans necessary to stay on your lines. You also have to be able to choose good lines quickly, without hesitation. And sometimes you don't pick the best lines. (See Picking lines and Getting out of the tracks.)
There's a big difference from picking the best lines and picking bad lines. Obviously, the best lines will get you where you want to go the easiest. Good lines will get you where you need to go, but you might have to work a little bit more. Bad lines usually put you out of position and into situations where there are few, if any, good options.
The tendency for most snowmobilers is to stay in someone's track. in other words, let someone else determine the line and break trail. If you have a good leader who picks decent lines, then it's easy to stay in tracks. (But easy isn't necessarily fun.) But if you follow someone who picks poor lines, it doesn't take much for the entire group to be stuck.
Unless you're in trees or terrain with limited options, movement and momentum are the key. Get your butt off the seat so you can be proactive to the change of slope. (See Mountain terrain is not level.) This is critical when your movement is uphill. Change in slope or snow requires instant change in body position and speed. Any slight pause or being out of position will increase your odds of getting stuck or losing your line.
(Tips No. 9-17 will be in the November issue.)