For home stays, how to I handle food the the sitter I hire? Do I leave them $, a fixed amount per day?

Through my experience being a in-home sitter, it's rare that an owner leaves money for food, although it's greatly appreciated when it happens. I often have people say 'help yourself to any food in the cabinets' but most of the time I bring my own, or go grocery shopping near the home. Do whatever you feel is right!

This is definitely an area you want to discuss with your sitter prior to the stay. As an occasional house sitter, I have always brought my own food and drinks, and the owner has shown me where the pots, pans, dishes, etc. are located so I can use them. If it's a longer stay, I will go grocery shopping on my own. I do not expect the owner to pay for my food, but it they choose to do so it's a nice perk.

As far as food for the pets, be sure to leave enough to cover the visit. Discuss with the sitter how to handle it if they run out. Either leave them money and the name of the store or have them pay for it and you reimburse them upon your return. In any case, as a sitter, I would be expected to provide a receipt for any purchases I made.