it's important to get skin tone looking right as most people know what colour skin is but trying to get the wall behind you looking right isn't as important as who would even know if it was right or wrong. So aim to get skin tones right use colour temperature to add to the mood you are going for and just do lots of experiments as there is no right or wrong, you might even start the next colour trend. There are some good tutorials on the Sony Vegas web site, Try looking at THIS to get some tips. One other thing about improving yours videos in general. Make sure the Go Pro is well mounted and not subject to vibration. Notice in the good example video you posted there are a number of different shots from different distances and points of view. Just having it attached to your helmet is not going to make an interesting video.