1.) DON'T BE A JERK!
You've got to lead by example. Strive to be who you hope they'll become. Want them to be kind, patient, understanding adults who save kittens and sponsor kids? Then try not to chew out the waitress for mushrooms in your dish. Want them to give their siblings time to talk and be heard? Make sure you give your spouse the same courtesy? For the most part your kids don't give a crap what you say but you can guarantee they see who you are.
2.) EMPHASIZE EMPATHY
Everyone big and small could benefit from a healthy dose of perspective teach them how to put themselves in someone else's shoes. When they misbehave ask questions that make them reflect on how that makes others feel and how they would feel in that situation. Part of the reason I think we act like such jerks as adults is because we forget that everyone is human. Teach them to extend the grace we'd hope to receive. Check out this awesome video from Sesame Street where Bruce Banner...I mean Mark Ruffalo helps explain empathy!
3.) KINDNESS OVER MANNERS
If you've ever watched any good 80s movie you know that you can be the classiest, most polished dude in the room and be a total tool. Teaching politeness without principles gives you fakeness. If you teach a child to be kind then please and thank you will be easy to teach. I don't need them to say yes ma'am to someones face and then be disrespectful behind their back. Raise real, authentic, loving, kind kids. After all manners are really just little random acts of kindness.
Oh and here's a bonus tip: PRAY!!! A LOT!!! The world is hard and tough. It is not easy to be a person of integrity. Often kindness and grace are viewed as weak. Ask God to give them tender hearts and a strong desire to do what's right. If you have a strong willed one, like I do, pray extra hard. I'll be praying with you!