Check the linkedin links if they are present. Sometimes those go to people who have absolutely zero information on linkedin. Thing is only a handful of people click those so deductively by doing your own due diligence you
will see the patterns of scams and be able to weed them out. All by trusting your process you will eliminate scams, important thing here is to have a process.
This, If the team is hidden that's a bad sign. Always check authenticity of the devs.
Another thing is to look at an explorer if possible - if the coin is premined or the owners are holding 50%+ thats a bad sign.
White paper is a big deal, If the white paper consist of less then 4 pages with mainly visual diagrams, that's a horrid sign. It's always best to read these.
Design is a big tip off too, if it looks like it was made in MS Paint in 1 hour you can tell that if they hadnt put much thought in the design they probably would do the same with the project.
The best tip off out of all is what I just quoted. Check for devs background. If there is no info on devs then tread carefully. If there is, make sure that they are who they say they are. I've seen people linking to fake linkedin accounts.