realsocialskills said:

Here are some rules of thumb:

Good friends are people you like. If you’re trying to figure out whether you like someone, here are things to keep in mind:

• Do you like being around them? Is interaction with them usually pleasant?
• How do you talk about them when they’re not there? If most of what you say is a complaint of some sort, you probably don’t actually like them very much
• It’s ok not to like people
• But if you don’t like someone, it’s probably better not to try to be their close friend or spend lots of time with them

Good friends are people who like you:

• Does this person enjoy your company?
• Do they respect you when you’re there? If most of what they say is insulting, they probably don’t like you.
• If they make a lot of jokes at your expense that hurt you, and mock you if you tell them to knock it off, they probably don’t like you very much
• If they act like they’re doing you a favor by being your friend, they probably don’t like you very much
• Life is a lot better when you surround yourself with folks who like you, and minimize entanglements with people who don’t

Good friends don’t creep on each other:

• People who insist on touching you in ways you don’t like probably aren’t very good friends
• People who won’t stop hitting on you or making sexual comments probably aren’t very good friends
• People who insist on talking to you about explicit sexual topics you aren’t comfortable hearing about probably aren’t very good friends.
• People who make a lot of explicit comments about your sex life or sexual desires without caring whether you want to discuss that with them aren’t good friends
• In some social circles, you might come under tremendous pressure to laugh this kind of thing off
• But it’s not ok, and life is better when you don’t tolerate it, and when you are able to create a social circle of people who don’t tolerate it

Good friends understand that you have a life outside them:

• Friends aren’t always available when friends want them to be, because they have a life and other things that matter
• Good friends understand that you spend time with other people, and have emotionally significant relationships that they aren’t part of
• They also understand that you have other things you need to attend to, such as work, school, taking care of your health, etc
• And they don’t treat it as an offense against them when you spend money on yourself, even when you’re buying something they wish they could afford but can’t
• Friends who expect to always unconditionally come first in your life are not good friends. (Even if they think they put you first. Even if it’s true, but it usually isn’t.)

Pay attention to your feelings:

• If you feel horrible about yourself every time you see someone, it’s probably not a good friendship
• If how you feel about someone changes a lot, there’s probably something really wrong. It might be fixable, it might be possible to work around it, but it’s important to figure out what it is
• If how you feel about someone is dramatically different when you’re with them than when you’re not, something is wrong and it’s important to figure out what it is
• For instance, if you consistently dread hanging out with someone, but enjoy it when you do, something is wrong (it might not be a problem with them, it might be social anxiety or something else. But it’s important to figure out what’s going on)
• And when you swear up and down that you like someone, but you also avoid them and don’t feel good when you spend time with them, you probably don’t actually like them as much as you think you do. Even if they have really great qualities.

Sometimes it’s not a bad friend. Sometimes it’s a bad friendship that can be improved by renegotiating boundaries:

• For instance, some people are good to spend time with, but not good to spend tons of time with. Captain Awkward has a good post on small doses friends
• Some people act dramatically different in public than in private. Spending time with them mostly or entirely in the setting you like them in can make the friendship a lot better
• Some people are nice to interact with in person, but not online, or vice versa. Being someone’s friend doesn’t mean you have to discuss politics with them on facebook, or that you have to engage with their derailing comments on everything you post. Similarly, talking to someone online doesn’t mean you have to go to their noisy parties
• Some friendships aren’t really personal relationships so much as alliances in which you trade favors. That’s an ok kind of relationship to have, so long as it’s actually equal and not exploitation. Trying to convert an alliance into a close friendship tends to end poorly though, especially if only one person wants that