Trump has to watch out for being SNL'd after his debate appearance. SNL killed it for Gore, just like they did for Dukakis. They learned their lesson after Gore, and now go easy on the Democrats.
Darrell Hammond is just waiting to bring his Trump back. Trump will have to be controlled and watch his mannerisms. This means avoiding excessive use of superlatives like "huge" and "tremendous," or he will be Palinized. He should be matter-of-fact, but confident and knowledgeable.
But most of all, he should be respectful of the debate rules and other candidates' time, unless the others keep stepping on him. Even then, he should be on the lookout for collusion amongst the candidates to try to entrap Trump into an ugly unguarded moment. They want nothing more than to force an angry moment where they can hammer Trump with questions like "is he out of control?" or "how would President Trump behave with Putin?" or "can Trump get along with Congress?"
He has to watch out for the caricature. To counter it, he has to show control, command, and breadth of knowledge.
-PJ
They've been trying to "Palinize" Trump since his announcement speech. I agree he needs to be matter-of-fact at the debate and let his positions on the issues slap the others in the face.