How do you do your own research if the coin is a good investment?
For me, I always look on the purpose of the project, the team behind it, what exchanges is it available on etc. And one of the important thing for me is the total supply of the coin.
I also research if the coin is Proof of Work (POW), Proof of Stake (POS), Pre-mined or other.
the popularity of the coin is needed if you going to invest like btc and eth now they are so popular so they good for investing you can also read all about the future plan for their coin because you can see the development by that,Moreover you can see also in trading site the market price if the coin is high so it's good for investing but still risky even they have value already