No instant smell test, just research, which covers points 1 & 2.

This is a great topic and I'm glad you started it. People always need to research anything that they're going to put money into. There are thousands of coins out there these days. A lot of them have a genuine use, but a lot are useless.
Research is the key. Never jump in due to FOMO. Always take time to understand what it is you're backing.