basically, everyone has different criteria for choosing an ico. they will choose ico who has good prospects to follow. usually, by studying ico that will be followed like reading the whitepaper, then we can find out whether the ico has good prospects or not.
Yes, reading and understanding their whitepaper is a great way to find an ICO. Plus if the ICO team makes a video about their colleagues who are working in their offices, it looks like a real project because their team really exists, not just photos and images that displaying on the site.