H. Jackson Brown, Jr. said, "Live so that when your children think of fairness, caring, and integrity, they think of you." I think that's some wise advice when dealing with issues of ethics and morality for a humanist. What is the wisest bit of advice you could give someone about how to live ethically and morality without a set of religious rules to follow?
Well.... respect is a big word. When you break it down it explains a lot. Just try not to hurt anybody. Hurt is another big word. If you know you wouldn't like something happening to you.... then don't do it to others.
From a distillation of reading books on game theory and The Art of Warfare by Sun Tzu, I would say that the best course of action is to always do more of the same unto others as they have done unto you. If we all behaved that way we do would do nothing but nice things for one another, right?