Said back in the day he would go to a local meet up and walk away with as many deals as he could afford. 

I'd recommend sitting down with an experience, licensed mortgage professional (direct non-bank lender) and run the numbers to figure out what you can afford and financing options. 

My feeling is giving a slightly better deal helps keep my peeps where I want them, which is a bit on the appreciative side - I am too small to afford too many vacancies.

As for the size, you will need see what your market needs and what you can afford to build.

@Adrian WydmanskiLiving in the Boston area I personally opt to rent and invest in the more-affordable markets outside of the city.

Granted, if you are able to select your own tenants and don't have to work with inherited ones that come with the property, and you can afford to have the property managed by a third party company, things can get a little less stressful.

Try to get a feel for the workflow and ease of use.Look for experience, affordability, and a personality that you click with.

For our first deal, we knew our number one goal was a cash flowing rental and, of course, something we could afford as first time investors.  

Not only do I know the area really well, but I feel as though there is significant potential for growth, and that area of the Washington D.C. area is one of the few affordable areas remaining.

These callers ask why these people are bailing after a year and I tell them that my guess is that they bought them because they could afford them but the buyers had very little experience with properties like these and the tenants that rent 450-dollar apartments here.