I posted this tree well story in the thread from earlier this year: http://www.epicski.com/t/118498/avoiding-treewells/60#post_1559020
Here's the tree well that almost got me a couple years ago:
I was shaken up enough after extracting myself I took that pic so I would remember to be more careful.
How did I get out? Dumb luck. I was upside down but facing the tree. I think that gave me enough space and air to breath after blowing the packed snow out of my nose and mouth. Prior to that I couldn't breathe, was panicking and thought I was a goner. I was lucky I was facing the tree since I could use my arms to "climb" the tree upside down until the weight of my legs was high enough out of the snow it allowed me to flip upright.
How did I get in? Dumb skiing. I was charging way too hard, and skiing alone. I popped off the knoll by the sun spot in the upper right of the photo, aiming to ski right between the tree I got trapped in and the tree on lookers right. It wasn't until I was air born that I realized there was a buried log in my LZ you can see in the lower right. I tried to make a hard right turn to avoid the buried log, dug my tips in, double released, and flew over the handlebars headfirst into the tree well.
What am I doing differently now? Trying not to be dumb, which is easier said than done. I skied these same trees (Upper Enchanted Forrest at Copper Mountain) this Monday, the first day they opened this season. It was very similar conditions. I skied with two friends and didn't charge as hard. Rather than the attitude of skiing faster because the powder will cushion falls, I try to think the powder could be my demise.
Not charging hard in snow like this is easier said than done when you've got that giddy feeling and are squealing like the geico pig ripping up pow pow. Skiing with competent friends all the time is also easier said than done, and your friends happening to be in a position to help you is to a large degree luck. For these reasons and after reading more and more about the risk of tree wells, I'm going to pick up an avalung pack and have it in my mouth when skiing terrain like this.
Update: I've got my avalung pack, a probe and a shovel. I'm going to buy a beacon exclusively for inbounds use and carry all that gear on higher risk days.