5. Picking Lines.
No, not pick-up lines. but the ability to pick and/or recognize potential lines and alternative routes. You should always be scanning the terrain, looking for an alternate route in case the rider in front of you gets stuck, makes a mistake or trenches out the line.
There're two parts to picking lines. The first is when you're out front or riding independent from your group. Even if someone else is leading, you may choose to take another line through the trees. The key here is the ability to look for gaps and anticipate potential gaps. A gap has to have the potential to get you in a situation where you have other choices. Most of us look for openings (spacings between trees) and angles (so you can square up to the face of the slope). If you have to choose a route that has challenges, it's better to address the challenges on the lower part of the hill than on the higher part.
The second part of picking lines is the ability to recognize "one-shot" lines. There is a misnomer that if one sled can make it up a line, all sleds can make it. Each time a snowmobile takes a line the conditions change for the next snowmobile. Some lines may only be suitable for the passage of one or two sleds. Lines can also be destroyed by a snowmobiler who trenches up the line or washes a line out. Some lines only have adequate snow for one or two sleds (rocky ledges or going over logs). The bottom line here is that you can't just follow blindly and wonder why you're the one who always gets stuck. Learn to read the snow.
6. Getting out of the tracks.
If there is a common desire amongst western snowmobilers, it's to have fresh, deep powder. When you're floating through untouched powder, you have the sensation of floating on a cloud. Yet too many snowmobilers will follow the leader and never get out of his tracks. There have been groups that hit a wide open meadow. and all they leave behind is one set of tracks. If there are four in the group, there should be four tracks through the meadow. If there are10, there should be 10. One advantage of this is actually a safety advantage. If someone in the group comes up missing, you can start counting tracks and see where/when he went astray.