I will typically check food and water when I arrive at the home, refilling water as needed, and refilling food around times specified. I'll also do a quick check for accidents in the house as I get the leash, and then I can take the dog outside. Depending on the dog's needs (I've had the most experience watching adult dogs), I can either take them for a walk or play in a backyard. If the yard has a fence and the dog is used to running around on its own, I will keep watch as they play, and make sure they don't get into anything unexpected (my dog at home is bad about eating random plants, so I've gotten used to keeping an eye on where the nose goes). For cats, I will change the litter as frequently as needed (typically I'll do this after checking food and water). If there are any medications, I will give at the time specified.