This may seem like a silly question but seriously how does one journal? My T wants me to start journaling and I agreed. However if I am going to journal I want it to be productive but I am not quite sure how to make that happen.

For example: I have realized through the grounding technique I have been practicing that I have a ton of anger boiling just beneath the surface. How would one go about journaling on the anger in an effort to discover the who, what, when, where, and why of all this pent up anger? I just dont know how to get started.