sefer/book on chachmas hanefesh needed

I am looking for a good sefer on chachmas hanefesh. I do not mean a recent book by a psychologist which sells well, I mean from a veteran. In my mind chovos halevavos has a keen perception of how people work and helps people understand themselves. There is a mussar sefer attributed to Rabeinu Tam which I seem to recall impressed me in this regard. There is also a sefer called Cheshbon Hanefesh which R Yisroel Salanter recommended, which is fantastic.

In the secular world, Dale Carnegie comes to mind. His famous books and lesser read ones are all full of keen and accurate perception into how people and the world works.

These are examples that come to mind. If anyone can suggest anything else that would fit into the above, I would appreciate it.