I dislike having a huge footprint for my art supplies and was having difficulty finding an "all inclusive" portable watercolor/sketch kit at all, let alone for an inexpensive price tag. So I made one.
This print took me about 17hrs on my Creality CR6-SE as I wanted it to be super solid and smooth.
This palette is made to fit a 3-layer storage container from walmart (link) on the second shelf.
NOTE: This currently appears to be off the market. May be able to find a substitute or resize to a different container? (link) (link) (link)
I've cut some watercolor paper and made a custom art block to fit the top shelf (This is a good tutorial link)
I put these supplies in my bottom shelf:
NOTE: there is still some room for additional supplies. Maybe 2-3 more brush/pencils can fit on the bottom shelf without causing it to not close.
Also if you make the top waterblock thinner, or after a while of removing them, you can fit pens/pencils at the top too.
This has been super handy for me to keep all my watercolor supplies safe, tidy, and portable for going out on adventures. I do also usually carry a small A5 sketchbook with me for when I want to be more of a "journaling" mood.