I don't know anybody who plays MMOs irl. As a 30-something mom gamer, it's not high on the list of things my peers are into. So when I play a game, I spend time getting to know people first, and then ask people I like if their guild is recruiting. I tend to avoid leveling guilds. I also avoid guilds that take all comers. I don't accept random guild invites.

In WoW, I leveled to 55 before joining a guild, after asking someone I liked if their guild was recruiting. I ended up being in that guild for over two years. In WAR, I found my guild by watching other players and looking at which guilds were doing what I eventually aspired to do in endgame. I put in an app on their website, chatted with them in game and in vent and got the invite. It was a bit of a blind thing for me, since I didn't really know any of them beforehand and I was a bit lower level than they usually accept. I had to go out of my comfort zone to put in the app. But it's been a good fit!