Make phone calls, drive for dollars, put numbers into a spread sheet, knock down a fence... whatever it is bring value to them.

If it is a house I have left offers on their front door, gate or even tracked down their other residence to knock on the door and ask.

And before I am knocked as attorney advising people to get professional guidance I will say that it costs much much more when a structure is not in place or just bought off of a website and something goes wrong.In your case, occasional vacant land flips are unlikely to generate much liability as compared to residential units do an LLC may not be necessary

Oh and might I add for a bit of newbie humor, that I checked on a house that looked abandoned so I knocked on the door to see if anyone was home...

Any advice when door knocking would be great!

If you have no knowledge of the process and you want to go with the bottom of the barrel pricing you are going to get an education from the school of hard knocks. 

Are you knocking down the existing properties on America St to rebuild or buying vacant lots?

Here I would door knock on pre-forclosure properties for potential leads.

Knocking on 50 doors in a week, you da man!

@Barbara Long just chalk it up to tuition for the school of hard knocks.