I ran my (P1e) game in a game store for years so I recruited there. I actually had a huge turn-over of players because people wanted to try it then didn't stick with it. One session had 11 players because everyone that was interested was interested THAT DAY for some reason. Next session was down to eight, then we settled on seven basically until the store went under.

I occasionally get someone referred to me, but it's rare. I scout anyone and everyone that even hints at playing TTRPG, though I don't necessarily recruit them if it's obvious we don't want to play the same game or same style of game. (I'll certainly invite people who play mechanically adjacent games though as long as they're interested in the same style of game.)

I just had a player inform me today that he's not going to be available to rejoin the campaign for at least a year, if at all, so I'm probably going to be visiting the local game store to try recruitment there. I may need to run some one-shots at the store or something to get people interested in my game since it's presently a home game and I don't want to move back to a game store (too much stuff to move as I use a lot of materials). I have one guy I might try to recruit as a player as well, as I was introduced to him as someone who could help him with exposure to the system a few years ago. His schedule doesn't seem open enough to join a regular game though.

When I first started playing, I played my first D&D3.5e game with people I met through meetup. This was back in 2004. Meetup might still be an option though.

I would not be above online recruiting but I only run face-to-face games, and I'm in Charleston, WV so it's rare that I'm in online groups with anyone within a two hour drive outside of Facebook. Facebook is an option, of course.

I also am not above trying to convert friends and family, though my immediate family has made it abundantly clear that they're not interested. I had an old friend in my previous campaign for awhile but I'm pretty sure he would have rather gone out to dinner, watched a movie, or played some video games, so he didn't stick around.

Really, I'd recruit just about anywhere. I'd not be above recruiting strangers that I just heard mention TTRPGs, though I might be more discerning with a home game than when I was running the game at a game store.