My intention was for it to be a natural how-to, hence the title Like a Normal Person.
Your behavior in any social setting will screen for people whose behavior is similar to yours. Thus, if you're happy-go-lucky, you will attract happy-go-lucky people, and if you are quiet and reserved you will attract quiet and reserved people. Therefore you should always be yourself because that is the only way to attract people who are compatible with your true personality.
HOWEVER, there is a difference between being yourself and being socially lazy. If you are a natural introvert that's fine, but you still have to make an effort to develop relationships. Relationships require communication to evolve and if you don't start conversations or make an effort to participate in conversations other people start with you, you will not develop relationships. Period. If you don't open yourself up, people will not be able to connect with you even if they really want to. And as I said in my original post, most of the time people will not realize that you're an introvert, they will take it personally and assume you're not interested in talking to them. So if I were an introvert, I might open up to someone by saying something like "I never know what to say to people at these parties, it always seems like everyone knows what they're doing and I don't." Now, this will likely repel the extroverts you say it to, BUT IT WILL ATTRACT THE INTROVERTS. They'll think to themselves, "I feel the same way!" Congratulations. You just connected with someone. You conveyed your person. People are not mind-readers, you must verbally open up in order to connect with them.
Now, introverts are somewhat difficult to be friends with because they don't often provide feedback. This is not an attack on introverts, it is simply an observation from experience. I have several introverted friends. They are great people and I love them. But I have to constantly remind myself that when I say to Ben (an introvert) "Hey Ben!! How's it going man??," he is not going to reciprocate with as much energy as I gave him. He'll say "Oh hi Andrew." And that feels like a letdown to me. I recognize that that's just who he is, and that it's not reflective of his feelings towards me, but it still kinda hurts. When someone is really excited to see me, I act excited to see them even if I'm not feeling especially excited to see them in that moment, because I know it makes them feel good, and I care about how they feel. This is not selling out who you are, or betraying your principles, it's making a social effort. I might follow up by saying I've had a rough day and I feel sort of down, in order to be honest with them about how I'm feeling and to let them know that it's not reflective of how I feel about them. Again, people are not mindreaders, you have to let them know how you feel.
So my recommendation is to start off conversations with high-energy so people know you want to talk to them, and then move into a more natural and open state of communication.