The first thing to remember is that no situation is going to be all about you. There are always other people that are feeling the impact of just about everything. Choose your battles wisely. Sometimes, it's perfectly fine to put on your diva shoes and demand some extra attention. Other times, you'll need to remember to hang back and let others have their own moments. Pay attention, and try to show empathy toward others. Let people know that you do care about them, their feelings, and their experiences. People will appreciate it and remember your kindness.
As tough as it can be, actively seek out the good in others. This can be especially effective when dealing with people you dislike -- when you have to put up with someone who annoys you, try to think of the qualities that they have which you can appreciate. You don't have to be best friends with them, but giving them a chance, or at least acknowledging that they aren't 100% awful can go a long way toward a better relationship.
Listen to people when they speak -- really listen! Ask them questions about what they say. Say their names, but not too often; people like it when other people call them by name. Use open body language; much of what we're saying is conveyed nonverbally, so remember that your physical cues are being read, whether consciously or not, by anyone with whom you are interacting. And don't forget to give people your attention; interrupting verbally is rude, but interrupting them mentally is just as bad. (And yes, people know when you're not mentally present.)
Listen to people when they speak -- really listen! Ask them questions about what they say. Say their names, but not too often; people like it when other people call them by name. Use open body language; much of what we're saying is conveyed nonverbally, so remember that your physical cues are being read, whether consciously or not, by anyone with whom you are interacting. And don't forget to give people your attention; interrupting verbally is rude, but interrupting them mentally is just as bad. (And yes, people know when you're not mentally present.)