Many coins are generally scam, as we know that, because developer team and improvement process do not work properly. However, there are a few projects which are really good at their job, their coins have a future. If we are looking for a good coin, firstly we should focus on the idea of project, developer team and improvement process of their technology.
People just have to list some obvious factor if the project is worth to put a trust.
There are projects that have an obvious shit so better be cautious dealing with this kind of project.
Yes before we go for it its much better if we check carefully first the project for us to dont have any regret of it even we do our best it's either failed or pass atleast we do our best.