I know when screening tenants you can’t choose based on race, gender, disability etc.

@Matthew Paul you cannot just flatly say that about any market. 

If you screen your tenants thoroughly it doesn't have to be an inconvenience either. 

House stayed flat for a while and 14 years later houses in the neighborhood sell for $600K . 

Bank turned us down flat. 

Being an older commercial building and having a flat roof this isn’t cheap, also not going to be easy with the other co owner, which leads me to the next mistake.

Lots of investor agents go to the flat fee firms which have the highest splits but those firms typically don't hold earnest money themselves which is an inconvenience during the deal process and don't have as quality of a reputation online so really depends what you are looking for. 

There are recommended screening companies there where you can do your research to see which company best fits your screening needs.

Good agents will screen the financing to make sure they're competent people who will close on the loan.

I'm comfortable with screening renters but wondering if anyone out there in Bigger Pockets land has advice on how to prevent problems, horror stories, things I should add in detail in the lease.Appreciate any recommendations.Thanks,Mike