You should always check for:
•Historical Data of coin
•The project concept behind the coin.
•The team involved in the project.
•The roadmap and current status of the project accordingly.
•Whether coin is part of pump and dump group if yes then join it.
•The traded volume of the coin and market capitalism for it.
All these and many more factors will define the goodness of coin if they are on the positive scale. You can't just make it short investment but the longer one to get hold on that particular coin.