I think it's very important to review many checkpoints before make a decision. I think team and advisers are very important and crucial factor. If they have enough experience and good history they have more chances. Also idea and their roadmap should be realistic enough. Because if something too good to be true...
I dedicate my great beliefs to projects that have new ideas and high-level leaders. Large communities and strong growth are also factors that I often pay attention to when investing in ICO projects.