warnings about rush

Literally just use common sense.

GET YOUR RECS. Don't talk about boys or partying. Don't badmouth any sorority or member or PNM. Or boy or frat. If you don't like your choices and you hear a rumor that the computer made a mistake, don't believe it because that does not happen.
Don't take cuts personally, it's only a numbers game and does not reflect on you as a person or mean that you weren't liked at a house. On the other hand, don't think you are too good for any house, give them all a chance; that house that wants that you're disappointed about may end up being your happiest place on earth after a few weeks.
Remember that you are not choosing so much as being chosen, and your choices are limited to houses that issue you an invitation to choose them back.