My proofreading tools

Binder clips
Post-it notes
Flags (provided by the publisher)
Red pencils and a small hand sharpener
A mechanical pencil
A finger moistener
A big pink eraser
My well-worn copy of The Chicago Manual of Style, sixteenth edition.
A big, clean table with nothing else on it that allows for spreading out sections of the book if necessary.
A clean towel to spread over the surface to be sure that there’s no grease or moisture that could get on the pages.
Lately, I’ve been using a pair of adorable little reading glasses.