I'm very selective when it comes to participating in ICOs, and I think we all should be. Choosing an ICO to participate in should be a process, you first see if the project their presenting is unique and is really possible to attain given the time frame they presented if they have one. Also see the number of participants participating in that ICO. You could also read reviews about the said ICO. If you feel that an ICO has met your standards then participate in them and feel free to quit early if you feel that the ICO is not going well.