I cant add much that hasnt been said, but I would stress the comment about the throttle being your friend. I have seen many newer riders shy away from the throttle because a racing motor sounds intimidating to them. Once I convinced my girlfriend of this she immediately became a better rider.
Challenge yourself every time out.
TRUE! Ducky told me when I bought his wife's sled "when in doubt throttle out" and that has gotten me out of several spots I thought for sure I'd get stuck. (course it also helps upgrading my sled from the 550 Cougar with the 136 track, but like Mafesto said, skill or lack thereof is also a factor)
Thing is looking at you boyz crashing into trees and such, sometimes I'm a little shy on the throttle boondocking. Need more confidence there (and staying away from tree wellls)