I don't really think of it as journalling to be honest, I think of it as the tarot book I want and which hasn't been written yet so I do it myself and that can involve a mixture of divinatory meanings and also background stuff (astrology, Wheel of the year stuff.)
I have a Thoth notebook which is background stuff, symbolism, my own thoughts, relevant bits from Crowley biographies, astrology etc
I have an Etteilla notebook which is translations
I have a Greenwood notebook which is Wheel of the Year associations and other pre-celtic lore and my own thoughts
I have a navigators of the Mystic SEA notebook which is me having waded through all the overwhelming, oceanic companion book info and annotated it into bite-sized pieces.
I have another notebook which is just all the spreads I have collected
I have a notebook which is only Lenormand translations/ my own thoughts/ meanings I have picked up
I have another notebook which is just numerology and all pip/1-22 associations
For all other stuff, sample spreads/readings etc, I think blogging is the way forward