I think something local gives a personal touch, (Welsh cakes, Devon scones & clotted cream etc.).
Teabags, coffee and sugar all in individual wrappers can be obtained from a cash & carry like Mackro, (I don't like half used bags of sugar or hall full jars of someone else's coffee.) Milk and maybe a bottle of wine. If children are coming, some little biscuits or chocolate bunnies, and most importantly a packet of dog treats if you allow pets!
I guess it depends how much you are charging, but if it is luxury standard, add in some flowers, soaps and enough dishwasher tablets for a few days. The clue is in the word SELF catering, so I would only expect enough on arrival to refresh me before I got in my own shopping.
NEW - "New Limerick Thread II 2016" (following New Limerick Thread
Alphalock - like wordle but harder!
What's one health habit you've started that's actually made a difference?


and was welcome indeed.