Also, because you will likely hold the property for many years, you will need multiple reliable tenants over time.Start by identifying a segment with a high concentration of reliable tenants through property manager interviews.

You can and many do but the best IMO focus their concentration and work life.

You can implement both strategies (concentrated portfolio and maybe trade a little more frequently versus passive buy and hold).

Class C neighborhoods, on the other hand, tend to have a higher concentration of rental properties, lower median income, and a higher crime rate compared to Class B neighborhoods.As a new investor, it can be overwhelming to decide between Class B and Class C neighborhoods, especially if you have conflicting advice from your conservative side and your financial brain.

In Houston we have the #1 market for job creation in the US, Low inventory and one of the highest concentrations of migration out of most US cities. 

We absolutely love Maui and jumped at the chance of owning property here (I say here because we are actually on the island now for a little work and vacation).I am by no means an expert and we mainly concentrate our efforts with vacation rentals in Maui, but I would be happy to answer any questions that you may have about investing in here.

I used to own in Essex junction, Colchester, and Winooski before I started concentrating in Burlington.  

Before that, concentrate on getting your deals and building some wealth, learn about correct insurance and proper management and get that solid in place - none will give you total protection and you need to combine them as resources in your toolbox.

There are differences in local rental regulations (registration, etc) place-to-place - for example, Elmira requires rentals be registered and inspected, but does not require CofOs except for new builds or particularly extensive renovationsHere's a fun article about one family that's working on a major historic reno in Elmira - I've heard we have the largest concentration of Victorian homes in the region! 

It is solid, but the job market is too heavily concentrated in manufacturing for my liking.