Answering these questions will determine which project you can invest in.
First of all why anyone want to invest in ICO?
What is the probability that the project is a scam?
If the project is not a scam what percentage may the price rise?
What is the return of owning a token? Is it just waiting for price increases?
At last how can I participate in the project?
What is the probability that the project is a scam?
Any new project can be a scam, so doing this steps may help to determine if this project is scam or not, but even this steps, you cannot guarantee the project is not a scam.
1- Check the idea of the project, is it new or old, if something new it will be a better, also this idea should be realistic and achievable.
2-check the team behind the project, you should be sure this team is a real (focus on founder and co-founder).
You can do this by looking to their linkedin account, check their social media accounts, check there history of activity.
3-Each project has an advertising video explaining the idea of the project, check if the founder appear in this video, if not, be careful, this project may be a scam.
4-check the soft cap and hard cap, do not believe that the low amount is better than high amount, the amount the soft cap and hard cap should be suitable to the project, this mean if the project big and the amount is low be careful it may be a scam, and also if the project is very small and the required of soft cap and hard cap is high.