> 1) Meet people doing hobbies/outside of work activities (You take art classes at the local community college, meet a nice girl, etc)
Good approach. In general, finding people like the original question suggests is a lot of work.
> 2) Meet people through dating sites (match.com, tinder, etc)
A great deal of work and patience - with no guarantees - but for some this could be preferable. Still, I'd hesitate recommending this.
> 3) Meet people through friends (Your friend has game night at their house, invites a single girl, you two hit it off)
Might bring good results, but you have to have good friends - both a lot of them, and those should have those required connections in society. Develop this even if it won't bring you to the main goal, the secondary goals are still worthy.
1) Meet people doing hobbies/outside of work activities (You take art classes at the local community college, meet a nice girl, etc)
2) Meet people through dating sites (match.com, tinder, etc)
3) Meet people through friends (Your friend has game night at their house, invites a single girl, you two hit it off)