It really is hard to find the best business to invest with, but there are some pointers missing in the list this thread has provided. So let me give you some realistic pointers that might help you make better decisions when it comes to investing. The first thing to consider when investing is the ability of the business model to scale. Meaning to say that, you have to ask yourself the question and that is “would this grow without a lot of finance?” “Would the company’s business model can be operated with minimum manpower required and also less marketing expenses?”
I believe this fall to the category of market assessment. I think even risk management belongs to this category. With market assessment, you are trying to figure out the market, its growth, downfall, risk, parties involved, competitors, feasibility etc. It is studying about the environment of the business model, where it will thrive successfully, it's short comings and possible fixes whenever a problem arrive.