Hi, sorry for the late reply.
Jason's right, you dont have to do anything technical in the camera. For artistic reasons, you should decide how you want your footage to look like. I knew I wanted to have a high contrast, over-exposed commercial so I shot it that way. But there's also other factors like costume, makeup etc...
Jason, the compact primes are nice, very robust, nothing bad to say about them at all. The 5D/7D on the other hand....well, depends on how you like to work :)