For example when reviewing the whitepaper, you should understand that ICO are mainly talking about blockchain technology project which to solve or improve the current existing problem in reality, no matter in which field. Therefore, the whitepaper should be indicating the problems first, and introduce how they will develop a blockchain technology, in a professional manner and data or model support.
Then you should have a look on their road map, whether they are having a sufficient and reasonable roadmap as an ICO project takes time to develop in both their sales part and development part. As long as you think it is reasonable, you can then proceed to (i) social media handling (ii) team / advisor for the project
(i) social media / community manager can show the relationship and the interaction from the team with the potential investors. The team may not be able to develop a super perfect idea and project, but from expectation and comments from potential investor, they can gain a lot information and knowing where to improve from different angles
(ii) for sure some famous or well-known tech developer would give this project a very good expectation, or else you can briefly read the profession from the team member or advisor. It is definitely a bonus if the team has developed similar projects before, experience speaks.
Although the review is kinda subjective, but as long as it can convince you, i think it worth your support and investment first. Failure of ICOs may not be due to the initial development process, may not mean it is a scam.