First assume, that EVERY ICO is made to bring money to the guys behind it. You should have a very good reason to invest in something, other than just the dream of getting rich. Bring up terms like development, support base, technology, uniqueness and usefullness. If you are not satisfied with the answers on only one of these topics, than it is probably not worth it.
Thanks for the comment. But these topics are not easy for newcomers like me to evaluate correctly, are there also some linguistic cues that you think are good indicators of the quality of the project? e.g. the amount of details provided, or whether its easy to read...