Personally I don't like neither helmet nor chest strap. Helmet video doesn't show anything, except what you see when skiing, and while it's fun to see that during skiing, it's super super boring watching that on tv or computer screen. Chest mount is a bit better, but still not really something nice. But 2 days ago, when I went just for quick early morning skimo to top of nearby mountain, I think I figured out pretty much best mount when skiing alone and you don't have someone else to follow and shoot you.
Currently it's still just try out, but I used my carbon monopod, which is nice 6 section one, so when not needed it's short enough to be completely in my ABS backpack, then I attached small piece of light wood on top to prevent it from rotating once camera is attached on bottom part of monopod. And it's stuffed in my ABS backpack upside down and extended as needed. This one was pretty much 1 section only, so only about 10 or 15cm above my head. A bit shi*ty to turn camera on and off, as ABS backpack should be fitted a bit better then normal backpack if you don't wanna die from it, and camera is too far away, or I'm not flexible enough
, to reach it while having backpack tight on. But position and point of view is pretty much best I have tried until now.