This is from "Speaking your mind in 101 difficult situations" by Don Gabor.
DO remain persistent even though you may feel like giving in.
DON'T respond immediately. Take a deep breath and count to ten.
DO listen for areas of agreement.
DON'T fight or get caught up in arguing over details.
DO think about what you want to say and then say it.
DON'T be overwhelmed by an aggressive person's behaviour.
DO exercize your right to reject a pushy person's advice.
DON'T let negative people squelch your enthusiasm or rob you of your dreams.
DO stick up for yourself and verbally aggressive people will respect you and be less inclined to pressure you in the future.
DON 'T give up on yourself if you get overwhelmed by an aggressive person. Practice your assertiveness skills and be ready for that person the next time.