I think one area people miss out on is local meetups in a tech area you know and want to work with. Networking with those people you’ll discover which companies are good/bad/etc and then also know someone there.
(a) it ruined the networking time for everyone else and (b) if I had an opening, I'd be less likely to interview them than before.
But perhaps I should give this a shot, just to put myself out there and see what happens.