Instructions
Reprimand the dog immediately whenever you witness bad behavior. Simply say "No" in a firm voice and, if necessary, pull the dog away from whatever it is doing. Be consistent -- if you let a German shepherd get away with something even once, it will think the behavior is acceptable.
If you can't catch the dog in the act, spy on it. If your German shepherd likes to get on the couch or open up the trashcan when it thinks you're not looking, let it think you have left the room, then wait with a squirt bottle to deter it.
Take away the opportunity to indulge in bad habits. If your German shepherd likes to destroy things when you're gone, take hit with you as often as possible. If you can't remove the opportunity to misbehave, wear the dog out through play and exercise. A tired dog will be less likely to bark or jump up on the bed.
Use positive reinforcement. Carry treats on your person at all times when you are working to break the dog's bad habits. Every time the shepherd does what you want it to do instead of its former behavior, reward it with a treat.
Work often on the "sit" and "stay" commands, using treats as rewards. Not only will these commands help you stop the dog in the act of doing something bad, they will also reinforce your dominance over the dog as leader of the "pack", making it easier for you to influence your dog.
How to Stop Bad Habits in a German Shepherd
German shepherds are known for their high intelligence and loyalty. They are an active breed that thrives on work, and they pick up obedience training quickly. However, they can also pick up bad behavior quickly, which is easier to stop than it is to begin. Bad habits in German shepherds often include barking, aggressive behavior, dominance and destructive tendencies. You can stop a bad habit in a German shepherd by repeatedly letting the dog know that its behavior is unacceptable.