I don't really have any rules, but there are a few things I try to keep in mind. A poster on another board I sometimes use wrote this (it was in response to a question about how to deal with everyday social problems like rejection, disagreement, etc), and it reflects the attitude I take:
Try to get rid of preconceptions you have about how things are "supposed" to be. At any given point, things can only be exactly as they are.
Getting upset now rarely changes things in a way that wouldn't make you upset in the future.
Realize that you can't control most things or other people. If that's the case, it does little good to get upset about it.
Other people do not necessarily share your preconceptions, tastes, etc. It's okay for people to be different than you.
Focus on doing things that you like, being ways that you want to be, and then you'll gain your own approval and not need others' approval. When others judge you negatively then, it's because they haven't dropped their preconceptions and haven't accepted difference. Maybe they never will. Whether they do or not isn't something you can control, so it does no good to get upset about it. Just try to be tolerant, helpful and accepting of them, however they are, as best as you can be. If you just keeping being "authentic", working on realizing what you like, what you think is right, etc., that's enough. Anyone else getting on board then is just a bonus, but not necessary.