1) Learn how to work with a null object. Parenting your camera to a null object will make camera movements exponentially easier.

2) Figure out all the idiosyncrasies of masks. My project would be nothing without them. Especially pay attention to :

a. Whether the mask is set to "Add" or "Subtract"
b. Changing mask position with nodes - Shift+Click on one of the anchor points on a mask. This allows you to alter the mask shape as you move keyframe to keyframe, creating the illusion of something growing or receding.
c. Working with mask feathering is tricky but can add a great illusion of depth if used correctly.