IMHO its a all of the above times, post cards, door knocking, SMS, face book PPC and ads in marketplace... 

why not knock on the doors in the neighborhoods that you are doing tear downs and remodels on?

After stopping by to see and knocking on the door, no answer to get in contact of the owner, I looked up to find the home is now 4  years delinquent on taxes.The house is needing much work unfortunately and with taxes being delinquent, the owner may not have the funds to rectify any of the situation. 

My wife and I are in the process knocking that consumer debt out so we have more wiggle room in our investment future. 

You got the first part down on the Know by door knocking. but I would dress in a manner that is reflective of the community you are door knocking in.

Ex: offer to put up their open house signs, offer to door knock for them or cold call expired/withdrawn listings.  

Have been renting it for almost 10 years with no serious issues yet (knock on wood).

Walk around door knocking and looking for distressed deals.

Anyone can market a house for 375k, but then knock off 75k for a  "just for you" price, but is it worth the 300k? 

On my new builds in Oregon that are in high demand.. buyers commish is going to be negotiated per deal.. for instance my last lot that will allow a knock out single level I am NOT offering any commission to the buyers agent I have a buyer for it.. their agent is going to list and sell their current home which is a 1.5.. and they will have to negotiate their fee with their buyer on my houses which is 850k..