I would say there is no way to make it sure . No matter how good project is , it still have really big chance to fail . I did invest in few ICO's that i though have really good potential become big , team , announcements , updates and so on made me do that decision . But if i look at current value of them , then its pretty sad . Usually developers of project is pretty active at ICO stage , but when it ends , then they change the whitepaper and tells investors that you are not investor , but token buyer =] Funny , isnt it ?