The guest room in my last house had blackout curtains, matching cotton bed set, extra pillows in the bottom of the wardrobe, which had one section empty for guest use, a bedside table and lamp, an empty chest of drawers, a selection of books and puzzle/suduko books on a book shelf.
Mini bottles of shampoo, conditioner, body lotion, shower cap, toothpaste, toothbrush, mini hairbrush, phone charger, etc.
A set of fluffy towels, slippers and a robe. Fresh flowers and a little box of chocolates or some fruit (depending on what the guest likes). I love looking after guests.
We also do a buffet style breakfast (tailored to what the guest likes) with rolls, homemade bread, preserves, pancakes, cooked bacon, eggs, smoked salmon, etc.
We have a decent coffee machine even though we don't drink coffee, as well as instant and flavoured coffees, fruit teas, herbal teas, black tea, etc.