I thought I might as well document one of my little "life hacks".
1. When I start a new book I stick a few post-its on the first page inside the cover. That way there's always some paper around to write notes on.
2. When I fill up a post-it I move it, either to the inside back cover or the inside front cover.
3. The added benefit of using post-its is that when I come to type up the notes (so I never lose them and can search them), the post-its stick handily to the side of the monitor.