you just need check few things
1 - Does ICO already has real business?
2 - Does ICO has real team?
In fact, that real team is always my own first target and once you can get that sorted out without some fishy stuffs being done, then there is no way I would not go further into trying to check the legitimacy and the whole business idea. A lot of people look at only the whitepaper, the websites and quick glance of the team and make decision based on that, but I believe experience will always teach everyone a lesson anyway.
Choose projects with high ratings in icobench or icoraiting.
What are these sites ? ICO reviews ? How reliable they are ? Could you please come up with their URLs if your time permits ? If these sites are being operated by trusted forum members then I guess we may follow them for recommendations.