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.
For me, the underlying criterion is the work of the team and the technology itself. If the technology I like and the team consistently performs the planned work and gives reports on the implementation, then such a coin will be successful 100%