It's about making friends.
Not necessarily the life-long, we-can-spend-years-apart-and-then-get-together-and-everything-is-the-same kind of friends.
But the I-met-you-at-a-party-and-you're-pretty-cool-to-hang-out-with friends. That's where friendships start. And that's where networking starts, too. Music promoters, bookers, A&R, other bands: you're making new friends.
That's all it is.
Sometimes you make friends with people you don't really like, but they throw really cool parties, so you make sure to stay on speaking terms. If your issue with them is a minor annoyance, you can keep it to yourself for the sake of the parties. If you really can't stand them, you end up not being friends, despite the cool parties.
Sometimes you make friends with people you really love to hang out with, but they kind of smell a little bit, or end up getting in fights with everyone you introduce them to. Even though you really like them, you end up not spending a lot of time with them because they make everything around them a little unpleasant.
Sometimes you meet people who are really boring.
Sometimes you meet someone who you have an instant, heartfelt connection with. Sometimes you meet someone and that connection grows slowly, but you're both super into it. Those are the really cool ones: where you get as much from the relationship as you put in.
It's the same with meeting people in music.
On invitations/getting press:
Do you want your friends to come to your house party?
You need to invite them.
They probably enjoy your company and love hanging out with you, but they can't come to your party unless you invite them. They simply will not know about it otherwise.
Do you want someone from a cool music blog to come to your show? Do you want someone to review your album? Do you want to know what people think about your music?
You need to invite them.
They probably love music, and maybe they'll love the kind you make, but you need to let them know you're playing a darn show if you want them to come out.
On developing a friendship/playing shows:
By the same token, you need to be very proactive in building relationships, especially in their fledgling stage.
Did you like that one girl you talked to at the party? Message her the night after the party and ask her how the rest of her night went. Say you want to hang out again. Find another time to meet up or another party to invite her to. Get brunch together. Whatever. It doesn't matter what you do, as long as you show that you are interested in keeping the relationship going. If you liked this person, the onus is on you, not them, to find out more and to keep building. If she doesn't enjoy spending time with you, trust me: she'll find a way out of it. If that happens, or if things get weird, move on along to the other friend you enjoyed hanging out with.
Did you have a great time playing a certain venue? Get in touch with the booker the next day and tell them so. If you want to play there again, ask for another date. Again, the onus is on you to stay in touch. You need to build the relationship. You need to be in charge of letting them know you want this to be a steady thing. If they don't like you or want you to keep playing, they'll let you know (or it will be come obvious after several attempts that it's not going to work).