Well, it's not really a REAL bullet journal. I don't have the patience to make sure everything is lined up and perfectly straight (though I WISH I did, when executed with exactness bullet journals are so, so beautiful!)
It's taken a decade or two for me to understand that if I commit to a habit, I need to have wiggle room - and while a perfectly designed and measured bullet journal might work for a few days, it's not something I'll keep up. So, messy, unmeasured journal it is.
My main focus is to break the day down into blocks for scheduling, but also keep a running tab of non time-specific to-dos. Between these two and all the extra space for notes, sketches and other blurbs I have found my holy grail for keeping the studio organized.
The physicality of the journal is super important to me. This journal isn't something that leaves my studio, and I absolutely have enough filled books already -- so the bigger the better.
This the Art Alternatives Giant Sketchbook (currently out of stock on Amazon, but I have few others listed in my shop here) and it feels like a wizard's tome. It's really heavy, but when I pull it out to plan the day and hits my table, it feels like this sacred moment before finding some ancient bit of knowledge... it engages me completely.
If you've never kept a bullet journal before, there are a bunch of great tutorials on Skillshare. To sign up follow this link and get access to their videos for 2 months for just 99 cents! I think the most important part is to find a system that clicks with the way you work and the habit will naturally take root. I couldn't commit to a perfectly measured out grid book, and I imagine in some one else may not be able to keep a book that was as scrawly and uneven as mine. Find what works for you!
If you do keep a studio journal of sorts, I'd love to see it! Comment below with an image or link of your journal, or share your organizational practices - maybe I can learn something new :)