1. Check the project - is it possible or impossible project, we can call it dream project.
2. Check the team - a whole team especially CEO and CTO and COO. Also dont forget to see who is the advisor. ( look at cindicator ) the advisor is totally legit.
3. Check the roadmap -  how long you willing to put your money in to this project, you can predict it from road map.
4. Check their github
5 check the top management linked in


Thats what i always do..