Your puppy learns appropriate behavior through successes that should be rewarded with praise and inappropriate behavior thought correction. The severity of discipline applied to a puppy should be minimal - only what is required to suppress an unwanted behavior. Anything more is excessive and unnecessary. The level of discipline can always be increased, but once excessive discipline has been used, negative side effects will occur. Remember, training should be a bonding experience for your and your dog.
From the outset, you must be clear about what behaviors you consider acceptable. Failure to do this can result in confusion and problems as the puppy matures.
For example, many owners encourage a puppy to engage in a tug-of-war game with a slipper after all, you are only playing. However, what you are doing is encouraging the puppy to hold on to things and try to win the tug-of-war game.