Here's another tip for you, the nicer you are to the sitter the nier they will be to you and you'll get more for your money. For example I have one client who usually goes out of town a few days a month. They ask that I go everyday for 1 hour to play with the cats, they let me watch tv and have a few sodas for me in the fridge. They cats are all over 15 so they want attention more then they want to play. So after I clean up after them and give them food and water I turn on the tv and sit and pet them and give them attention, but most of the time I'm there I figure I'm going to watch tv and drink soda at home anyways and I know the cats get lonely so most of the time I stay there for much longer than an hour. If a good movie is on I'll stay for 2 hours or sometimes even longer.
We also leave daily notes where we write about how the cats were that day, and what we did with them. We write down if they were sad or if they were really playful, we let you know what games we played with them, if they are eating well and so on. We also leave report cards to let you know if they have been naughty