One sure way is to know if a project is scam is by checking out the developers linkedin profile that is if the project is not an anonymous one.... If you search and you don't see their linkedin or however u find it but it something related to the project is not found on the profile then it is definitely a scam
Yeah. And it's also important to be able to contact a team
Most important is read the whitepaper, the team behind the project, the partnership, Roadmap and the platforms.
There's a project that are scam but it's easy to know if it's reliable and credible.