Backyard videos are tough. The scene is always the same. It's generally fairly boring scenery, so you have to do everything you can to make up for that.
Leave out all the falls and all the repeats. No offense (I was at this point once, too) but I don't want to see your friends landing switch 5 times in a row. I saw it once, now show me something different. You're trying to make up for the stagnant setting, not highlight it with skiing that doesn't entertain the viewer.
Stabilize your camera. The shaking was unbearable.
Move your camera! Not all shots have to be stationary and wide! Do some tripod pans, do some dolly shots, anything to make the shot more interesting.
I think you need to watch some videos and see what you like/don't like about them. Rail jam videos will apply to this too, because they're filming in one, relatively drab location the entire time. I don't mean to videobomb/self promote but I figure this might help; this was my most successful backyard edit. Maybe it'll give you some ideas.
Luke Hagearty Summer Contest from Miloš Atz on Vimeo.
Good luck.
M