The biggest thing to consider is: if you sell your house, will you also live in the next one?

I like Columbus Ohio because I see it being one of the biggest metropolitan cities in the next 10-20 years, all signs are pointing here!

The neighbor might be the biggest burglar in the town for all I know.

My biggest regret is not signing up to get locked into 20% off annually.

The biggest red flag is that the potential tenant isn't even good at potential fraud.Do a thorough background check to make sure they're not just giving you some nonsense or friends to pretend they're employed. 

My biggest issue with snowballing is my family's budget must be paid by a decent percentage of the income I make

My biggest advice would be to take your time and do as much research as possible.

I should also mention that despite owning multiple properties with very little leverage on them, real estate isn't my biggest holding.  

^^^Biggest driver of wealth in real estate is the long-term appreciation, especially in Denver.

I'd say my biggest mistake was not researching the property manager properly before hiring them.