It helps draw (and keep) your attention when you review your notes.

A few guidelines:

• Use colors
• Highlight headings
• Leave enough space between sections (or make them otherwise distinguishable)
• Use a readable font and don’t make it too small
• Incorporate images, charts and sketches where you can
• Number the pages

This is what some of my notes look like:

(I’m not sure this will help anyone, but it’s my main method to get myself to do something for school, so I thought I’d post it anyway. Aside from the fact that you’re more likely to study off of material that looks nice, I really like making things look pretty, so the whole formatting and structuring thing lets me get familiar with the study material while I do something that I enjoy.)