Arguing -- My father always said, "Never argue with ignorance." Honestly, it's probably best to never argue with anyone. Discussion is good, and debate is okay, but arguing is usually a lose-lose situation.
always, always trust your first gut instincts. If you genuinely feel in your heart and soul that somethign is wrong, it usually is. Love this. It's so true. And once you go upon trusting your first instincts never look back on it. You know it was the right thing to do. Never second guess your first instinct.