What daily exercises can I do to master narrative design, storytelling & messaging?

I'll give you two things you can do here.

1. Write about Narrative Design or your version of the framework and publish it. I do this on Linkedin. Find examples, ask questions, examine different parts of the process, try and upack it for others. There is an endless amount of ways you can add to the discussion. This will help you get better at thinking about it and it'll attract people who are interested in using it.

2. Read. To become a better storyteller and writer you have to be constantly learning from the people who do it well. Easiest way to do that is by reading more. Don't just read business stuff too. Read a wide variety of books, fiction, other industries, podcasts work too. The more you have to pull from the better.