if I think personally a safe way to invest in cryptocurrency is :
1. the project runs according to the roadmap and whitepaper that has been made;
2. cryptocurrency that we invest in already has a product;
3. the team always updates about the progress that is happening in the project that we invest;
4. invest in project that are in the top 1-500 in coinmarketpcap (have a high volume);
5. the project we want to invest has been running for a long time (if I personally never invested in a new project), because investing in new project has a greater risk than we invest in old project.
It will be very helpful for people who's just about to start investing in crypto to listen to people who has been doing it for a long time and has experienced different downfalls in crypto space for they already know what to do and what to avoid doing. It will also be very beneficial for a new investor to read books about investments, study what is inside crypto space and how you should act, decide and move within it. But aside from that, always weigh thinhs carefully, weigh everything and think if they can be of help and not just leading you to wrong decisions.