If you don't mind abbreviated words, slang, or incomplete thoughts written on the page, and if it's enough for you to go back and know what you meant, then by all means write casually. I think there's something to be said about writing things as they come out instead of editing them to make sure they're perfect. The only person you need to be sure is satisfied with your journal is yourself.
However, I do not want to just use formal talk only when I am not comfortable with myself or what I am writing, but when I am writing down some goal or aspiration I talk formal.
You could also have 2 journals. Left brain,Right Brain.
Good luck 🤗
In terms of frequency, anything is better than nothing so I just do it when I can.
Start with whatever you want to explore, and always keep in mind that you can always journal again the next day, so if you’re having a rough day, or even only have time to put down a short paragraph for the day, you will have time to do more entries, and because it is only YOUR journal and your journey, you can do whatever you like with it.
There are days where I have drawn a picture as my journal entry for that day, or written a poem, or just talked about a movie or a piece of art or some pseudo-philosophical ideas that I want to explore at the time.
The sky really is the limit, so don’t limit yourself, but if you find that you are having trouble getting started with an entry, then you should start writing about how you’re having trouble finding a place to start, and then the rest of the entry will take care of itself.
Let the ideas flow like water from your stream of consciousness onto the page, and I guarantee you will eventually learn a lot about yourself and how you approach the world.
This captures the authenticity of your thoughts.
I write my journal according to my mood and keep it truthful and simple. I don’t sugarcoat any of my feelings. I present it the way it has been. I feel that nowadays people share what happened to them with family, friends or relatives. But rarely does anyone share how they felt when a specific incident took place. So with my journals or diary i write how i felt in a specific situation. I at times use my mother language other times i write in a casual manner.
So i suggest you choose the manner according to your feelings
It may be formally if u write it alternetly casually of u write it by ur heart
I am not saying this way of Journaling is the only write way.
Journaling is for you for 1.reflection
2. Accountability (to get to know that all things are going fine or i need to change the process)
3 . Visualization
This technique is used to visualize your dream place either job or your future self .
I keep mixture of formal and informal sometime i write formal like bullet points and sometimes i write in paragraph to express my feelings .
But make sure you make journal interesting use icon and creativity to express your thoughts
So next time you write, it feel like fun to you
Thanks for asking this question
Remember that you are not being judged for what you write. Set your intentions and your journal will help.