I agree honest communication is key, you need to talk with the owner about everything about the dog, that way there is no surprises and you as sitter know how to handle it.
during a meet and greets keep an eye on every detail. How the owner presents himself and the dog, and how the dog behaves to a new environment. For sitters that offer drop-ins, and if you see the owners house, check for details can tell you if the dog has anxiety. You need to be prepared and educated on how to handle animals with anxiety.
During the stay send a lot of good pictures, no blurry, no bad light, owners really appreciate a good picture and a video!
Be on time always and discuss food schedules.
If you feel uncomfortable with something, say it! if there is something bothering you about the dog behavior is very important to tell the owners, and keep proof.
Offer a little more in your services for free, is like an investment. Do not charge for every extra minute. I've seen some clients bringing their dogs from other sitters that charge for extra minutes. in my case I have a pond and my clients can get a little bit dirty, so I offer free baths if the dog stays more than one week. Also, I offer my clients to leave their cars parked in my property when they are traveling out of the country, that way they save money in airport parking. my clients are very happy and I have return customers. If that's not your case offer at least a brushed dog.
Give to the owners free stuff (little treat bags, printed pictures).
