[lwlml]

Use the same size notebook.

Set aside front-matter pages for indexes and update them whenever you review the contents.

Write the subject, date and page number on every page.

Throw the notebooks away when they're more than ten years old. You're a different person today and if you didn't use the idea then, that idea probably isn't going to be relevant today.

Bad ideas will decay. Good ideas will echo. The hard part of the experience is knowing that 99% of your ideas will never be done.