Check out this concept called "Bullet Journaling" (lots of YouTube videos on it). That, with a dot grid notebook, could do wonders for keeping your notes organized.
But for the writing itself, look into "calligraphy basics" - doesn't mean you have to write every letter in a fancy way, but the mere exercise of practicing it will at least build better habits for letter height (which makes everything more legible).
Lastly, I recommend switching to a fountain pen (yes). I don't know what it is - but I just care a bit more when writing with one. There are cheap ones (Pilot Kakuno Fine), no need to get fancy.
But for the writing itself, look into "calligraphy basics" - doesn't mean you have to write every letter in a fancy way, but the mere exercise of practicing it will at least build better habits for letter height (which makes everything more legible).
Lastly, I recommend switching to a fountain pen (yes). I don't know what it is - but I just care a bit more when writing with one. There are cheap ones (Pilot Kakuno Fine), no need to get fancy.