How can i teach my dog to fetch?

[Wonster]

I have a young dog that loves to play with anything he can get a hold of. He loves balls,sticks, ect. Hell even play with wooden sticks he finds laying on the ground. Hes only a year old and ive tried everything i can to get him to fetch. when i throw the ball, pretty good distance but not too far, he runs directly to it and gets it, then when i am holding a treat and say good boy come he just ignores me and runs aroung the yard with the ball and then lays down and chews or leaves the ball behind and gets distracted with something else. Any help would be greatly apreciated. Thanks.