
Usually, you should be creating something "close" to the original features. For example, in my opinion, this is not true for feats in 5e, which are heavily disbalanced.

Note that it only works if you assume the original devs did a decent job in balancing whatever they published. You can either create a rating system of your own or use a well acepted rating system from the internet, e.g. The first (and most important) step is to compare it to official and published race/classes. These are the most important things I've learned in the process. I'm constantly creating new stuff for fun. Some background: I love to homebrew things.
