A five-subject spiral bound notebook has been a fabulous choice for my classes. Composition books are great but each year I have students that run out of room. They then change to a different notebook and it isn't nearly as organized as the first.
Table of Contents - Keeping it simple!
Foldables - My students favorite way to add content to their notebooks.
Illustrate the notes - Even students who aren't artistic appreciate a quick pic as a reference.
Fold those handouts/worksheets - In an attempt to keep as much information on a page as possible, students were allowed to fold their handouts and glue them in.
Diagrams, Charts, Organizers, and Everything Else...