Evaluating potential ICO will be easy if you already know what the project is all about, what's its pupose and what market it intend to enter. The market needs will tell if that ICO will become successful since the current market situation is the reason behind the development of such project. Investors can also tell if that project will likely to succeed or not so you can also check their feedback.
This is an important thing to consider first on where market it would enter. I have seen lots of projects are focusing on the same market or thing to progress which i do see that it would flood and turns out on having less interest and most likely they will fail.I do rather choose up into newer and unique projects which dont really have much competition into the field of progress which higher chance on seeing a potential would be always there.