I invest in ICO only when there are famous personalities in the development team who have already created something in their life, in general there are few such ICOs, it seems to me that smart scammers can make such ICO that it will be almost impossible to accuse them of scam in the stage of fundraising, and when there are eminent developers in the team, the likelihood of a scam is much lower, since they risk their reputation and it will be hard for them to hide with money, so in my opinion ICOs are  building mostly on trust, so you have to trust people whom you are giving money.