Each home has to be viewed independently as each has unique characteristics.

I what type of characteristics should I look out for when interviewing or what are some questions I should ask?  

In term of reward, I know the reward of mortgage note, but for tax lien it's kind like semi gambling.

One model I’m seeing investors doing is the rent by the room strategy / padsplit.IF done right, you can turn a single family home to function like a multiplex - increasing the cash flow by double, even triple oftentimes.Has to be the right property of course / layout / characteristics to minimize drama and conflict between roommates / tenants since it’s a longer stay than STR and spaces are shared but with the right set up and systems in place in can be extremely effective and super profitable.You can easily switch from STR to MTR since it’s already furnished and just make a few tweaks.I can definitely help you put some ideas together or connect you with some investors I know doing it in Jacksonville FL. 

They were not as concerned with the characteristics of the property.  

There's still opportunities within this space, but you will have to focus on properties that possess the characteristics I noted above, not the clearly marketed opportunities. 

The appraiser should generally try and rate those important characteristics in order.

And then marketing to those characteristics. 

From there you can identify properties that possess the base zoning and characteristics you are seeking.

These factors contribute to each opportunity possessing unique characteristics for every investor, in addition to the learning gained throughout the process