These were usually houses that didn't sell and the listing expired, I called owner directly or knocked on their door, craigslist for-sale-by-owner, or it was October/ November, and the seller knows they won't sell a house now until the spring because winter is coming (I'm in upstate, NY), and nobody leaves their house when it's freezing out. 

We managed the properties and at about 20 minutes it was easy to get to but we didn't expect the tenant to knock on our door. 

My method would only work if you're going to contract a crew to knock the job out quickly.

Knocking on wood now.The duplex is pretty much ready to rent as-is.

School of hard knocks + BP, REI meetups, and a library card.

Find their mailing address on the recorder website, and send them mail (or, as i prefer, knock on their door).

If you're serious about buying this, I would walk the units only with the owner, you need to be able to talk to him in the place, take his temperature to see what he is thinking and use every minute to knock down his expectations.

I'm not knocking designers.

And, on "occupied,do not disturb"......always go knock on the door, see what you can learn.

In fact, I'm toying with the idea of doing some value add to properties I'm under contract with (knock on wood).