The basic of self-change
To become a better public speaker: Record yourself and watch that video. The whole one. You will know where you need to improve.
To have realisations about yourself: Write a letter to your future self. Read those letters. Send some more into the future.
To get better at making decisions: Write them down. Review them sometime in the future.
The basic is this: Externalise your thoughts, feelings, beliefs, hopes and dreams. Get comfortable with the discomfort of seeing, hearing and experiencing yourself.
That's where your change start.