1. The idea of the project should solve real problems.
2. A team of people with experience and reputation, live contacts, an opportunity to talk with the team
3. Presence of finished product.
4. compliance of information in all documents, clear description of the project, no suspicious information when verifying the domain
I fully agree with DmitriySar - as long as I believe in their idea and the whitepaper looks not copied or strange I think about investing.