There are many ways to identify a fake project such as one of their presence and answers to investors' questions and a trusted exchange of ICO identities. Keep views project team everyone's profiles and locations, research their products, even if any of the information they provide is questionable or unreasonable then think that the project is a hoax.
for some projects maybe we can identify it ourselves. however, for professional scammers, it can be difficult to do research on your own. sometimes you need help from forums to do that. however, there are still quite a few people asking about project scam on this forum, and it really helps.