To be clear, you don't need to be an extrovert to be successful, as people like Bill Gates, Albert Einstein and Lady Gaga will tell you. But you do need friends, not only to help you advance your career, but to up your health and longevity, too. These are the essential strategies the smartest people always use to get them.
1. Put yourself closer to the other person over and over again.
We're programmed to naturally distrust and dislike the unknown, which is unpredictable and, therefore, perceived as incredibly risky. But if you stick to your guns and find sensible, safe ways to get in another person's path over and over again, eventually, you move from unknown to known and lose your scariness. This is the rationale behind the exposure theory, which assumes that people will like you more if they just get exposed to you more. Be brave and don't give in to the temptation to pull back just because the first meeting was a little uncomfortable.
2. Look for a common point.
You and your potential friend are two entirely different people. You're not going to have the same views on everything. But focusing on a common point will help your listener feel like they're more of an insider with you, rather than alienated and distant. It also helps you come across as more open and cooperative, as you resist conflict and don't shut them down.
3. Give empathy, compliments or both.
When people are interacting, they want basically only two things--to feel understood and included, and to feel like they have personal worth and value. When you let another person know you "get it", or when you stroke their ego with a few kind words or gestures, you disarm them and engage memorable, positive feelings. They might not remember the verbatim of your conversation, but they will remember those powerful, fast-trigger feelings--and want to come back for more. And as the saying goes, kindness begets kindness. If you listen well and demonstrate real thoughtfulness, they'll mirror it back to you.
4. Put preconceptions aside.
People subconsciously push their own ideals, expectations or feelings from the past onto their listeners. For example, if you had it rough and were mistreated as a kid, you might assume your listener will eventually hurt you, too. Psychologists refer to this phenomenon as transference. To really make friends, you have to be aware of this tendency and acknowledge that your listener is new, unique and their own person. Don't make them into someone they're not! Once you identify and admit your biases and dig deep about where those biases are coming from, you can get to know the real individual and connect better.
5. Watch your language.
I'm not talking expletives here, although I personally feel there are a host of other intelligent words to express yourself with instead of those. What I mean is your use of phrases and words like "should" or "have to", "nonsense" or "silly" (e.g., "You should have...", "Oh, that's ridiculous..."). This type of language implies you somehow know better than your listener and is judgmental. No one wants to feel inferior or like they've made a mistake, so if you really want to teach something or offer your opinion, don't blurt your initial, uncensored gut reaction. Instead, try phrases like "May I tell you why I would have [x] instead?" or "I'm curious to what brought you to that conclusion" or "Help me understand..." There's more to try on this helpful phrases list from the U.S. Institute for Environmental Conflict Resolution.