You should have a lease agreement for the roommate prepared by a landlord attorney.

You should get an attorney-prepared lease fit for your situation.

That more than prepared me for managing my own properties.Biggest mistake?

There's a long checklist of items to prepare before you start your direct mail campaign:1) Is it scalable (manual letters aren't) 2) Are you using your time in the most efficient manner (handwriting is ok for starting, but you need to hit 1000s of targets to get the responses to grow your business) 3) Is your message correct for that market?

Be prepared to act fast, as desirable properties are still moving quickly.For Sellers: With rising median sale prices and strong demand, you can confidently list your property knowing that buyers are willing to meet your asking prices.

Therefore, since this loan will end up sitting on the lender's balance sheet, you should be prepared to pay an interest rate that would make sense for that lender to have their money tied up without earning the additional income they would earn from selling their loans at a premium on the secondary market and being able to re-lend and keep flipping the money. 

If they are not prepared to live in this area that is not my responsibility to ease it for them.

.- Prepare for Eviction if Necessary: If the female tenant refuses to leave and cannot pay the rent on her own, you may need to consider eviction.

Since this has happened multiple times, both sides should be prepared to bring documents showing what investigation and what corrective action they took (hint: they likely have none). 

Prices are so high and rents haven't kept up as well so if you're leveraging I'd be prepared to put down 35-40%.