Rediscover what made you friends
One good way of getting over a fight is to remember the reasons why you became friends in the first place. If you have a favorite activity that you like to do together, take some time to do it! Talk about the things you really like about being friends, and the ways your friendship makes life better.
Leave the fight in the past
It's common for many people to hold grudges or "keep score" when it comes to past arguments. But if you want your friendship to get stronger, you have to put the fight behind you. When future conflicts come up (and they WILL), don't bring up the old fight or the emotions you felt during it. In other words, let bygones be bygones, bury the hatchet, and let sleeping dogs lie (add whatever clichés you want to this list!).
Once the fight is behind you, you can concentrate on just being friends again. Treat each other with fairness, sensitivity and respect, and keep looking forward, not backward. When conflicts come up in the future, you can try to take care of them right away, rather than letting them build into the kind of fights that can do real damage to your friendship.
Now let's look at what you might do if you try all of these ideas, and the problem just seems too big or nasty to fix: Ending Friendships.