Anyways I want to send my tenant a letter introducing myself as well as my family.

I came to find out that the house was on a drug infested block, with boarded up abandoned homes next door.He said that the appraisal was off because they used the wrong comps and urged me to get a new appraisal with a different appraiser.

I then sent out "yellow letters" to all the properties that met my criteria.  

In the long run, newer subdivisions cost the government more than inner city blocks.2) Older businesses that sit on expensive land in city centers pay less tax than newer businesses, forcing newer businesses into greenfield developments even as older areas with good infrastructure become pockmarked with parking lots and abandoned sites.Rent control won't solve them, but a more rational taxation system will. 

I have read about driving around to look for houses and mailing letters to people in a certain zip code (I am not going to do that.)

Our current residence is a 3/1 1420sqft and is located in a very nice, small town in DE with a very sought after school district 3 blocks from the school.

A two-condo regime can be great, but if you have big trees in the wrong spots, you can get blocked by the city permitting process.

If you do, the same can be true about a house 2 blocks away or 2 miles away.2 - Controlling your who your neighbor is. 

I was suggested to write a letter to the other homes and see if anyone responds.

Since you been around the block a few times and plan on making a few more rounds, would you be willing to make a generalization on how you approach homeowners as oppose to investors?