Don't complain to people you're conversing with about things that don't affect them. It just makes our life seem sucky and makes you out to be a negative person to be around.
Don't talk to people about boring things going on in your life.
Don't pick at your face. It will only scar your face and worsen blemishes. Instead put on benzoyl peroxide stuff.
Speed walk when possible.
Don't let people make you act a way you don't want to act. Act in ways that you like. Respect yourself enough to not try and impress people with the way you are acting/ things you are saying- you just annoy yourself. Silence is nice sometimes, too. Don't forget that being an observer instead of the performer is good. You can just share your observations when they are good instead of trying to think up good ...