1. Don't date your friend's ex.
At least not right after their breakup and she's still not over him; she'll definitely mind. If you do, your friendship will most likely be compromised, and you'll also make it awkward and confusing for the three of you if you guys hang out.
2. Don't reveal a friend's secret.
Because some stories aren't for you to tell. And it's called a secret for a reason! Be trustworthy.
3. Don't leave a drunk friend alone.
Always have your friend's back when she's vulnerable or when her guard's down. Don't give people the chance to take advantage of her.
4. Don't flirt with the friend's boyfriend.
Why on earth would you?! Sure, they're not married yet so what you're doing isn't illegal or anything. But you'd be disrespecting your friend and her relationship.
5. Don't let your friend date someone who's taken.
Unless of course there's an open relationship going on—then that's fine. But if not, don't let your friend ruin a relationship. You don't want her to be that kind of girl.
6. Be there for her after a breakup.
She feels shitty and miserable. She might hate on the world and every guy out there, so she needs to know that things will be okay and that there are people there for her; she doesn't have to feel very lonely.
7. Let your friend know if she's dating a jerk.
You might be caught supporting all her decisions and trying to be happy for her in spite of knowing the guy she's with is a jerk. You don't want to interfere, and that's understood. But if he's really not a good guy and you have proof, the right thing to do is to let her know. That's it; don't tell her what to do with the information; let her make her own decisions still.
8. Let your friend's light shine.
People need their moments of glory, especially when they deserve the recognition. So when she's gushing about something exciting in her life, let her, and be happy with her and for her.
9. Tell her if she has food in her teeth, lipstick on her teeth, smudged makeup, tagos, and something stuck on her shoe.
You wouldn't want to make her a laughing stock and embarrass her, right? You shouldn't.
10. Rescue her from a guy she doesn't want to talk to.
You'd want her to do the same for you. Don't let her feel uncomfortable for long!
11. Boost each other's confidence.
We all need our support group. It's hard to boost our own self-esteem and keep our heads up when we feel really insignificant, so it's wonderful to have a friend to turn to and make us feel better. Be that person and gift for your friend, and believe in her.
This story originally appeared on Cosmo.ph.
* Minor edits have been made by the Femalenetwork.com editors.
SCREENCAP: Pitch Perfect 2/Universal Pictures (2015)