I write all my work in the following format. Some teachers require this format or you don't get a grade for your work:
Problem #123
Given: Problem Statement
Find: List parameters (x,y,z)
Solution: State solution with all steps clearly indicated in descending fashion
BOX: Final Answer with units
Don't box your answer, you don't get credit. I personally use this format on ever single homework. My helicopter teacher made us create flow charts for all our code we used in numerical solvers in the homework we turned in. We were not allowed to turn in the code itself.
I try to be neater and neater with my notes. My class notes are very very neat now. When all you have in the class is notes (no book) you better well take good notes.
I hate scribble, and I don't write in my books. I underline and highlight stuff with a ruler, and only if vital write on the margin a small clarification if aboslutely necessary. I don't lend my books because I don't like people turning the pages fast causing them to crease, or pointing at something in the box with their pencil tip putting pencil marks on it. I get pissed.
If anyone asks me for a book for a class, I say I don't have it anymore.