You come home and see disaster has struck. Your favorite shoes lie on the floor in 10 pieces, the garbage is tipped over, and Fido sits there looking innocent as ever. He's not a lost cause yet, though. You just need to show him that you are the alpha dog.
Take your dog on a pack walk each day. While a normal walk involves your dog walking in front of you, a pack walk requires that the dog stay either beside or behind his owner the entire time. Do not allow him to freely sniff, and only allow him to relieve himself where you deem appropriate. This shows him that you are the leader.
Eat before you let your dog eat. Once you have poured your food, do not allow him into it. Make him stay. Place a snack for yourself near his bowl so that he thinks you are eating from his bowl, and eat your snack before you allow him to eat. Alpha dogs always eat first.
Walk through all doorways and up and down all stairs before your dog does. If he starts to go before you, make him stay. Once you have gotten through first, you can then tell him to come.
Ignore your dog when you first come into the room or house, even if only a few minutes have passed. This shows him that you do not give him your attention based on when he wants it, but when you are ready to give it.
Stay at a higher height than your dog at all times. Do not roll around on the floor with your dog, as this puts you in a submissive position in his mind. Do not allow him on the bed unless invited. If you do invite him, keep him at the foot of the bed. If your have a particularly aggressive dog, do not allow him on furniture at all.
Make eye contact with your dog and hold his gaze. Do not look away first. When the dog realizes you mean business, he will look away. This shows him that you are the alpha dog and, therefore, the leader of the pack.