Preferences books that get used

One page per guest. Pillow, water, coffee, dietary, allergies that are real, newspaper, cabin temperature, tenders, whether they want to be asked or left. Update after every trip. Date the update.

Share it with the chef. A preference the galley does not know is a preference you failed.

Do not write gossip. Write what serves the next crew. 'Likes a quiet breakfast on the sundeck, hates coriander, will ask for the printer' is useful. Character studies are not.