The prettiest notebooks in the class are almost never the top scorers'. This is not because prettiness hurts — it is because the time it takes is time not spent doing problems.
Pick one notebook per subject and one system per subject. Cornell-style works well for humanities (cue column on the left, notes on the right, one-line summary at the bottom). For math and physics, a single wide column with worked solutions is enough.
Never copy from the textbook into your notes. If it is already written down somewhere you own, do not write it again — reference the page number.
Reserve the last five pages of each notebook for your 错题本 entries in that subject. This keeps mistakes close to the material they came from.