Here are a few rules to abide by when in a friendship with someone to ensure that this friendship may flourish and blossom into all that it can be:
1. Be Yourself: Many teens struggle with maintaining their own identity with such pressure to conform to the status quo, especially once they become part of a new group of friends. It is important to stay true to yourself and present yourself in this genuine manner in order to be truly happy and have true friendships.
2. Avoid Gossip: It is important not to spread rumors about your friends, whether it is done intentionally or 
unintentionally. It is easy to spread a nasty rumor unintentionally by discussing an issue about someone with another friend; the conversation can easily escalade into a discussion about all of the negative things about that person. This discussion and attitude then is easily transferred to other friends, leading to an unintentional rumor that could really hurt someone’s feelings and jeopardize your friendship with that person. Set a good example; you wouldn’t want someone to talk nasty behind your back with all of your friends now would you?
unintentionally. It is easy to spread a nasty rumor unintentionally by discussing an issue about someone with another friend; the conversation can easily escalade into a discussion about all of the negative things about that person. This discussion and attitude then is easily transferred to other friends, leading to an unintentional rumor that could really hurt someone’s feelings and jeopardize your friendship with that person. Set a good example; you wouldn’t want someone to talk nasty behind your back with all of your friends now would you?3. Defend Your Friends: At some point in time, someone is bound to question the integrity of one of your friends publically or privately. Take this opportunity to defend your friends honor and defend them, showing your faith in your friends. This is the sign of a true friend.
4. Protect Your Friends: It is always a smart and responsible idea to look out for your friend’s best interest whether it comes to alcohol, dating, drugs, school, etc. This doesn’t mean being their mother and telling them what to do, but expressing your concern and opinion could potentially help your friend see the impending danger in their decisions.
5. Boyfriends/Girlfriends: It is a golden rule of thumb to absolutely avoid dating/hooking-up/crushing on someone that a good friend of yours has previously dated/liked/hooked-up with. Even if your friend says its “ok”, it never really is. Respect your friend’s broken heart when making decisions on who to date.
6. Return the Favor: A good friend will lend a shoulder to cry on, a jacket when it’s cold, notes for a midterm, and everything in between. Friendship is a two-way street, so return the favor! This will make your friendship stronger and avoid anyone feeling used or abused.
Sources: Teen Advice