Establishing trust with your dog
If your dog runs across the street after a squirrel, your heart is in your throat out of fear of him getting hit by a car. When he returns, you're angry and scold him. How does the dog look at this? First he chased the squirrel which was fun. Then he came back to you and was punished. What you actually taught him was that coming to you is unpleasant.
One of the most important commands you want your dog to master is "come" when called. To be successful, remember that whenever he comes to you, be nice to him. Don't do anything the dog perceives as unpleasant. If you want to give him a bath or a pill, don't just call him to you. Instead, go get him or call him, and then first give him a treat before the bath or pill.
No matter what he may have done, be pleasant and greet him with a kind word, a pat on the head, and a smile. Teach your dog to trust you by being a safe place for him. When he's with you, follows you, or comes to you, make him feel wanted.
If you call him and then punish him, you undermine his trust in you. When your dog comes to you on his own and you punish him, he thinks he's being punished for coming to you. You may ask though, "how can I be nice to my dog when he brings me the remains of a chewed shoe, or wants to jump on me with muddy paws, or when I just discovered an unwanted present on the floor?" At that moment in time that he doesn't understand that he did anything wrong. He only understands your anger - but not the reason for it. As difficult as this may be, you have to grin and bear it, lest you undermine the very relationship of mutual trust you're trying to achieve through training.
Punishment after the fact is cruel and inhumane. Even if the dog's behaviour changes as a result of being punished. It changes in spite of it and not because of it. The answer lies in prevention and training. Prevention means providing plenty of outlets for his energies in the form of exercise, play and training. It also means not putting the dog in a position where he can get your brand new shoes. Training also means that you teach him to sit on command so he doesn't jump on you.