The following will be a superficial list on how to be a good debater at BUD (and with people in general).
As hard as it may seem when you are actively debating the opposite side of your opponent, you are not necessarily seeking to win, but to engage and listen to your opponent.
Please have an at the very least basic understanding of what you are talking about. Be honest if the topic gets too far out of reach for what you know currently.
No one likes fallacies, and using them deliberately makes you suck (sorry). The important thing to remember is to always have a "if A then B therefore C" attitude when debating.
Don't just compromise on your beliefs so you can win an argument/seem less extreme in your thinking. If you have a commitment to a belief, you should not be shy with said commitment (at least in BUD).
Hopefully you learned a thing or two, and I'll see you at the seminar.