Doing lots of research on the coin project itself. Be sure that is going to give it a little back of investment in worst case scenario.
Doing the proper research is more important than doing a lot of research.
1.Making contacts with the team members is also very important. If its a fake team then most of the team will be fake and wont be responsive to contact.
2.Again advisors can be contacted for involvement in a project but then again most advisors tend to not reply to any personal messages at all.
3.Another important aspect is the whitepaper. Plagiarized whitepaper is an immediate red flag and 99% chance of being a scam ICO.
4.Doing your person audit of the ICo funds can be useful but most of the financial info will be locked away from public.
5.Evaluation of the domain name. A newly registered domain raising suspicions.
These are few of things I do before investing anywhere. But honestly speaking I prefer bitcoin over any altcoin.