Determine your goals, and then structure your real estate investing to achieve your goals.As you expressed, building a portfolio of rentals is a sound strategy. 

One angle to consider is picking the rental based on the highest achievable Debt Coverage Ratio (DCR).

With all things being the same, I want to spend as little as possible and achieve the most cash flow.

Make sure to check out your local BP meet ups down in SoCal - great resource and will be very helpful for you to ask people in person how they have successfully achieved what they have.

Although this is a common statement, I have recently committed myself to achieving this goal, and believe it is a very realistic, and attainable one. 

I will not let hard situations stop me from achieving my goal.

My plan has yet to be developed but my strategy is to achieve that mainly through buy and hold in Northwest Indiana.  

People vary widely on what they consider a good ROI as there are other factors to consider such as appreciation, your personal goals and how you are using property to achieve certain goals.  

If you have other goals, we have to know what those are before we can recommend a course to achieve those goals. 

C-class investments generally offer a 12% or higher return but based on the elevated risk involved, these numbers are tough to achieve and even harder to maintain.Hope this helps.