Some tips that can help you get good photos of a dog include using treats, tailoring to the dog's quirks, and using a camera extender. Catching a dog when he is relaxed is also a great way to get a good picture.
To use a treat to get a good photo of a dog, give him one or two first to get his attention, then use the third to direct his eyes to where you want him to look. If the dog has quirks, such as drinking out of the toilet, encourage him to engage in the behavior for a great photo opportunity. A camera extender is also a good bet for a good dog photo since he does not see a human and does not get distracted. This is best for natural shots.