I have a nice big yard with a nice fence and a doggie door, so my dogs are very happy and are house trained. Well, at least they don't pee inside the house. But lots of times I'll catch my black lab going outside and peeing on the outside of my house instead of in the yard! How can I stop that?
Put dog on leash. Walk outsite with him. Take him to the area(s) that you want him to pee in/on. Praise him for pottying there. Do not leave unattended in the yard until he is consistently going in the preferred place.