I don't really know how is the specific ways to know a project going to be scam or not. But I have my own due diligence to analyze an ico, it is:
- read the whitepaper
- who is behind the project. Even if it's a decentralized project, we have to know it, at least the advisor.
- information on Ann thread.
- the website and its design
- roadmap. It's all have to be clear.
- demo product