I don't think that there is a way to 100% avoid investing into a scam project. Of course there are ways or things that you should do to minimize the risk of picking a scam project to invest in but you can never be 100% sure. I would advice to always look up the whitepaper, look if it is well written and not only a 10 page copy and paste whitepaper. Then look at the team, check their linkedIn or Xing profiles and see how old those profiles are. Ask critical questions about the long term goals and how they want to accomplish them in their telegram group and see if the Dev Team is answering and what they are answering.