I'd say 10% at least, but talk to a local property manager about what's realistic, given the turnover in your area.Find out whether your local county has an online Property Tax portal, and whether you can plug in the property's address to get historical tax data to use for your assumptions. 

Rather than butt heads with these folks we do deals virtually throughout the US. 

I'm new and just upgraded to PRO and ready to kick 'RE Butt' in 2020!

I just upgraded to PRO today and am ready to kick 'RE Butt' in 2020!! 

Because Texas is such a pain in the butt to get one, I would say hold off until you have deals going - in other words, making money.  

A few of those properties actually showed a negative cash flow while others were marginal ($100-150) after plugging in my own numbers

I was just there to look At their fridge and found a cigarette butt under the fridge and didn’t say anything.

Plugging in your numbers, the mortgage calculator says it would cost me $550/mo for taxes/ins/loan.

It’s not a major difference in the grand scheme of things, but every little bit helps.In my book, The Hands-Off Investor, (shameless plug—BP launching it in the spring) I dedicated a whole chapter to waterfalls and have examples of both methods of returning capital.  

Dont just pull a number out of your butt or say hmmm it would be nice to make 25K.