The one of the snowboarder is alright, it would be better if there was sunlight on him, or use a flash. Or if you wanted a silhouette of him, then shoot it a stop or two down. I really like the contrast in the chairlift/moguls shot, but it is a little crooked. If you were going for that, then that's cool, but I usually try to make my pics so that vertical & horizontal lines are straight. The waterfall shots & are pretty sick too.
I have a few of my pics posted in the pictures section. If you go to my profile & click on the pictures tab, you can see the ones I've posted.
I don't pretend to be a professional, but I am really into photography, & I feel I have a pretty good eye for it