Depending on local regulations, you can mix up STR/MTR/LTR. 2) Get systems in place in those exact cities; 2 PMs preferably via NARPM, 2 high quality inspectors, and rotating book of handyman, 1 lawyer, and a credit union contact for leverage along with investor friendly nationwide lenders.

Without the upside of a good neighborhood and/or quality property, I don't love it. 

Brandon Turner outlined this method in one of the older podcasts and there are previous posts in the forums.  

You get so much wealth and start getting older you enjoy the business but focus on quality of life more and memories. 

I've seen folks charge as high as $5,000 to $10,000 for tax planning and tax preparation, But i also know high quality folks that have fees are around $1,200 to 2k.

https://www.biggerpockets.com/forums/12/topics/1122318-quality-turnkey-companies?

Well-maintained homes: Homeowners tend to spend more time and money maintaining their homes, which contributes to the overall quality of the neighborhood.

The real estate investing industry uses "Classes" to rank property performance risk, but there's NO agreed upon industry model:(Here's what we use for our Metro Detroit market:Recommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?

@Mitchell RosenbergAnother approach is the elimination method.

@Jemini LeckieRecommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?