Its hard to suggest anything without knowing where your talent level is or seeing the footage you’re working with…
Are you competent in rotoscoping? Motion tracking?
Spend some time and watch some sports… Watch the commercials and the openers. A pro football game would probably be your best bet with your subject. Pick a few clips you like that don’t look too complex and try to reproduce something similar.
Or pick an effect you like that you can’t do and come back to the Cow and get the help you need =)
Brian