In your opinion, what should parents try to teach their children when it comes to friends and behavior around others?

Today a very interesting discussion has taken place on Fluther regarding the importance of a child thanking someone for a gift. Some feel it’s unnecessary, some feel it’s important and a good lesson to teach kids.

A few days ago I asked a question about my daughter being excluded from playing with other kids because she didn’t have a certain toy. In discussing this with one of the other moms, the mom told me that she teaches her kids to be strong. I was talking about my daughter being hurt by being excluded and she was saying she teaches her kids not to be hurt by stuff like that (but she has twins, so worse comes to worse they have each other).
http://www.fluther.com/193541/what-is-your-opinion-of-children-telling-another-child-that-unless/

Anyway, what do you think is important for parents to teach kids?

Is saying thank you and other social niceties important? Or do you feel that kids will learn that stuff when they mature? Should children be taught to be strong? To what extent should parents try to guide children as far as the choice of friends?

My friend said she tells her girls (the twins) not to just have one best friend, but to have many friends. I don’t guide my daughter in that way. I figure whoever she wants to hang out with, as long as it makes her happy, it’s fine with me whether it’s one person or ten people.