As I known, ICO is a kind of risky investment. Similar to the IPO which is the form of invite for capital investment, but when buying IPO, investors can research the information about the company they invested, find out about official finance reports and be protected by law when joining. In contrast, ICO projects are often rather ambiguous and unprotected by government so the risk is so high for investors.
So how to evaluate a potential ICO project, look forward to receiving comments from you

I evaluate them by their Whitepaper, roadmaps and the most important one is the team behind it and its impact on the investors. I participated on many iCOs already but one thing I had noticed is, when there are few investors joining the ICO 98% it will be a big fail. So in order to get a successful ICO, you need to go where theres a lot of investors investing on it. And this is the main reason why other people go for the hype in joining the ICO cause even if the whitepaper is good but theres only a few investors on it, this will turn to be a big fail.