Read the AICoin whitepaper if you can. The way they handle tokens is the most appealing I have seen to date.
In general I try to assert whether or not there is a real/functional product to be had in the future. I also try to assert whether or not the ICO founders have an incentive to run with the funds instead of completing or working on their product.
I will certainly read it, thank you so much! I have a doubt: how would you assert whether or not the founders will run with the funds?

I mean, that's totally not our intention... but this is a question that I always put on myself since I started thinking about it....