However, if you want to take risks, the best bet is to consider the following
1. Founding team - Experiences, pedigree, past performances, vision and skills
2. Product-Market fit - Does the solution actually make sense or is it a fad ? Is the value proposition unique ?
3. Traction - If the product has a MVP, consider how many users it currently has. Consider product stickiness (ie : repeat customers) and profit margin
4. Runway - How long can the start-up run with the funds raised. Will it be enough to really sustain ? Will the start-up become profitable by said period.
Here is a great post about ICO research:
https://bitcointalk.org/index.php?topic=1923939.msg19087583#msg19087583