You write about the symptoms of anger and how to control them.
Yep, good idea.

Yet you did not mention the important aspect of working with the causes of anger and how to work with being positive.

For suppressed anger can be very dangerous. It can either leak the cold way of revenge or set off some fears and neuroses.

Likewise, ignoring the causes of anger does not get you anywhere.
The is no justified anger. It always relates to some personal deficit. Good to be aware of it. Trying to be authentic does not mean having to act it out.

Being positive then ought to be a matter of conscious choice. Like turning back into the situation (physically or mentally) and trying to figure out, how one could have helped the other person. Good exercise, not always easy though. But its worth it.