Having twins, and having four boys, I have struggled at times to teach manners. Having good manners gives your children confidence in social situations, especially when adults are involved. Overall I am very proud of my sons and their manners; here are a few things that helped me help them learn:
Manners start at home. Model for your children that people we love and live with deserve the same respect and courteous treatment as strangers. (Yes, even older and youngers siblings!) Have and help your children practice good manners like saying, "excuse me", "may I?", "please", and "thank you.
Respect for elders. Older people deserve special treatment simply by virtue of their age. Show them respect by giving assistance whenever you can, and encouraging your children to do the same. We go to neighbors homes and shovel snow, and the kids take turns mowing in the summer.
Respect and awarness of others in public places. Ever wonder when all the nagging reminders of "inside voice" would pay off? Teach your children to hold open doors for those passing through and to walk on the correct side of stairs and hallways.
Telephone manners. Teach children the basics like answering the phone with "hello" and offering to take the phone to you when the caller asks. Also, make sure to teach your children proper ways to take a message. Make sure to go over safety precautions with your children as well.
Conversational niceties. Teach your children how to respond when someone speaks to them. Practice looking each other in the eye when speaking to one another, and speaking up.