There are plenty of women out there looking for action, but you'll need to take some initiative in order to find the majority of them. Sometimes you'll get lucky and one will move in next door, most of the time you'll need to be proactive.
Online: Easy way to find them, but you'll probably find the easy pickings in your city within the first month of being on whatever dating site you're using. Don't worry, in a couple months there will be a fresh crop to pick. When I use these, I hit them every few months to find the new crop and it's humerous to see which of the old crop and still hanging around.
Bars: I know you say you wish to avoid these, but these are still good places to find one nighters. Sure, sometimes you go fishing and don't find anything worth keeping, but it's still a worthwhile pursuit.
Apartments: Make friends who live in apartments so you can meet the tennents. These places are time efficient. There will almost always be one good pick in any decent sized apartment building. Use kids, dogs, or whatever as an excuse to talk to them if you're a little on the shy side. It really doesn't matter. These probably won't be true ONS, but it's easy to make FBs this way as the girls are often married or have bfs that are underacheivers.
House Parties: I'll admit I haven't been to one of these in quite a while, but I can tell you that going to these things is highly productive. I'd find these things out of the city and all the locals knew each other. I think showing up at these things as an outsider is especially productive. Almost every timeI've been to one of these things some chick has wanted to bang me. Just make sure it's not a sausage fest before going out to BFE.
That's plenty to get going