It took me a decade + of just playing and gigging and whatever to build my old network. I literally started on the street busking.
 
If I were able and willing to start over I'd just go check out some of the open jams and really just gigs being put on by the local bands. Just talk to people and see who's up to what, who's lookin' for who.
 
Answering random ads... yeah that's generally going to lead to disappointment (or getting outright robbed).
 
It's a tough nut fershure... especially nowadays. I used to kind of go the "couch toad" route when I could when hiring new members. A couch toad is just a hang around who'd come to practice, knew the band, came to gigs, helped out and generally fit in. If they played an instrument and we just happened to need that instrument replaced... well, enter the "couch toad". lol
 
If you have a van... well sh*z... you really don't even know how to play really. You can just pick up a bass and try to stay sober during the gigs.

Another way is to find out where bands (that play what you're interested in or are of the right age group) are playing and go see some.  That way you'll get a good idea of what their doing and it's always easy to meet the members.  Then ask your questions! 
 

Thanks for the suggestions, guys. What I've been doing so far isn't working, so it's time to try something new.

Yep... I was going to say to visit the music stores. Grab a guitar and set and play a bit.... you'd be surprised.... people are listening and they might just need your talent... I've put together more than one band this way and got hired into a few others in a similar manner.

Check out the bulletin boards, of course you can post your info but scan it for something along the lines of what you're looking.
 
Walking into the gig of another band has it's pro's and cons.  I remember how I looked at musicians coming in saying they played guitar or drums.... yeah... right!  On the other hand, you never know.... you could be walking into a band that's fixing to fire the guitar player and they're looking for someone and you're that one.

Take a gig you may not like all that much anyway..... when you're out there playing, other bands and musicians will see you and hear you. They will become aware that you're in town and how good you are so when a spot opens up in a better band, they may call you up.

I know a few older musicians who use technology and do a two man band, oldies, cover band gig.... they play the good old stuff, travel light, play when they want, get along well and only have to split the money 2 ways.

slartabartfast

How Do You Find Other Local Musicians?

Ah, the Portland method!