Personally, I usually read : Whitepaper, compare the previous projects same idea (concept), detect advantage project.
Other, I check roadmap, team, web, social media...etc
In team, check for their profiles on LinkedIn and try to interact with them.
In social media, search about their ratings and their social media presence like Telegram, Twitter...
I feel safer to participate in a project clearly defined roadmap and experience team.
Besides, I will check on some web review Ico...Ex : Icobench, Icorating, Icotracker..etc
And what about you?