For me I depend on the team activeness. Reviewing their team and advisors profile is also an important factor, I always appreciate those ICOs that spending their time for roadshow, for introducing their project, to get themselves involve to different blockchain conference, sharing and updates on social media platform. This is easy but also take times for effort to build up the network and to see the teams' willingness to learn and to share.
Second is the road map and third is the whitepaper. As long as it can convince me, and no duplication or plagiarism from other projects, i think I am willing to get involve to their crowdsale.