Always ask for references and examples of similar projects (pictures)The Red Flags you have to Avoid:Lowball bids (too good to be true often is).Poor communication or delays in responding.Hesitation to provide references or sign a detailed contract.Cash-only deals or pushy behavior to secure the job.

With C or below you probably can't avoid some of it so I'd go with a recency bias, ie anyone who has a long period of time between their last eviction and successful rentals other places will be a safer bet than the guy that just got evicted. 

While BP has a rent estimator as does rentometer.com (both allow a few free uses, I believe), I agree with @Zachary Deal that your best bet is to seek out guidance from either the listing agent or a property manager well-versed with the area. 

I looked in thrift stores and on FB Marketplace for my house, but found poor selection, and none of it fit in with the decor I was going for.

Don't bet on passive appreciation, just forced appreciation.

In fact, most made money betting on both sides.

My interest was sparked this summer after passively listening to a free version of "Rich Dad, Poor Dad" while doing home reno projects around the house.

In fact, I've got some bets in the markets that hinge on this happening.

If it goes well, investo more.If it goes poorly, figure out why and maybe you picked the wrong market, the wrong team or the wrong property Class. 

My greatest pain point is not that the deals failed, although that certainly adds salt to the wounds, it's the poor communication, false narratives, chasing (almost begging) for updates, lack of full disclosure, the smoke and mirrors, etc.