It might sound silly, but learn how to get stuck. With this, you will get plenty of experience getting unstuck. The guys that have ridden for a long time still get stuck, but it usually only requires minimal effort to get them out. The new guys can auger a fair size crater when they are done and are completely sacked out.
When you get into a situation that you think you might get stuck, start looking for the place to get out the easiest, then go there instead. Sounds silly, but it is just a matter of turning out a couple seconds sooner on a hill. Sure, you may be stuck, but at least the sled is already starting to come around. Sidehilling over a tree, if you feel the momentum won't carry you all the way past the tree, drop down and pick a different line while picking up momentum in the process. Stay out of depressions, there is nowhere to go but up if you are buried.
I don't mind helping people get unstuck, but "stupid stuck" all day gets old fast.
Also, if you are driving up to help someone else get unstuck, don't box them in with your sled. Give them some room that gives options to get out. This one annoys me when you almost get someone popped out and some joker parked his sled in the way, or his helmet/gear.