One way and one criteria that I always considered in choosing a good ICO is that they have a very informative, substantial whitepaper that is really clear to their goal and objectives and also they have a team that is composed of experienced experts in every field of their project.
That's right, that is an important thing that we must do before actually plunging into participating in ICO. And in addition, I always see how many communities they have and how active they are in discussing in the community and always providing updated news about the projects they are running.
According to the technical document, it is not always possible to understand whether the project will be successful or not. There are very professionally made technical documents while the project is still unprofitable.