C) Equipment: Buy more/bigger/faster washing & drying unitsMix and match till you hit the sweet spot that works for you.

Peoples have different degrees of risk tolerance so there is no best way to go about doing things, just find a sweet spot as far as risk/reward that works well for you and your investing goals.Some people choose to sell their properties after awhile to buy new properties (hopefully at below market value) and thus earn instant equity by buying correctly, and it also resets their leverage back to a higher amount thus amplifying their gains. 

For example right now I’m checking the neighborhood around Five Palms Dr and Sweet Maiden St. in the 78242 zip code of San Antonio, and it doesn’t show any units for rent.

As guru podcasters taught you, you immediately order cost segregation study, in anticipation of a sweet tax relief.

When the lender at Griffin does answer they are nice and sweet  but I think it would be better if they answered the phone consistently and got the job done.

Along the lines of what @Eddie T. alluded to, the "sweet spot" would be if you can find property for $40-45k that rents out for $8-900/m.

In your case, owning and living in one side of a duplex for $200/mo out of pocket (after paying your taxes, insurance, operating expenses, and debt service) still sounds like a pretty sweet deal.

Put your sweet equity into the property, refinance the place and pull the money out for your next project.

With my nicer rentals I am not getting this type of return, but the appreciation has been super sweet though!

Pretty sweet!