Research in more detail about the project including the developer,whitepaper,roadmap and the project team, then avoid it when you see something suspicions about the project.
Exactly, that's the real solution to find it out about the project is a scam or not. If you do research about everything regarding the project which has provided by the team then you will definitely get the idea about the project. Most of the people haven't taken such kind of actions and after that, they'll regret it.