Just thoughts on something that appeals to me too
I started just skiing around decorative trees on a run.
Pop in and out of the edges of a 'glade' run which is fairly sparsely populated. Be careful to keep your speed down until you're confident you can spot branches/roots at (or more importantly just below) snow level.
I think I'm more worried about catching roots and other hidden dangers than I am worried about hitting trees!
Then do the gladed runs slowly and start to ski a few turns without stopping.
Eventually go through smaller gaps. Keep an eye on how the snow lies, blows and shapes differently in trees. Notice how branches look just above and under the snow. Learn how to plan a route 1, 2, 3 and 4 trees ahead - I find visualising a red line stretching out and around the trees works for me (I guess this also fits with looking at the spaces too).
Try slowly skiing more densely packed runs and then go back to sparse runs - makes it much easier.
PS One of my big complaints about ESA Aspen - all those trees are way too tightly packed together. I did suggest releasing beavers but that just upset the locals