Strategies on using cash flow on rentals

[Mark Smithey]

I am 31 and own 3 rental properties and cash flow at least 250 on each. 

Wanted to see what others do with the cash flow, I DO NOT need the cash flow for living. I make 400k+ a year and I live off that and buy rentals with that as well. 

My goal is to buy 3-4 rentals each year until I get 50+ units. I will probably move into multi-family and apartments at some point.

I have 3 loans with a balance of 76k, 110k, and 142k. My thoughts were to use the cash flow from all 3 to pay down the 76k loan first and just pay the minimum payment on the other 2? Good strategy or not? 

Currently I just pay monthly on each not exactly what I get in rent. I have also not re-fi any of these, if I did I could pull out 50+ on each. 

Any thoughts would be appreciated...