Dogs, like people, make mistakes and there will be times when they do something wrong, regardless if it is intentional or not.   Any time they engage in behavior you deem unacceptable you need to correct it immediately before you give your companion the impression that his actions are acceptable.  Furthermore, your corrections must remain consistent because even letting him get away with bad behavior once is enough for him to do it again.

That being said, you need to know how to best reprimand your pet without causing negative repercussions that can damage his self-confidence and result in behavioral issues, such as fear or being overly submissive.

For starters, under no circumstances should you ever hit or kick your dog.  Not only do you risk injuring him but you can actually make the situation worse and cause him to become fearful, which can lead to aggression and destructive activities (I.E. chewing).

If you want to scold or stop your animal from continuing with his current act, you can always tell him "No!" sharply and follow up your command with another action to draw his attention away from his previous deed.  For example, if he was chewing on your shoes, say no, take away your shoes and replace them with a toy to show him what is acceptable and praise him when he redirects his chews.

Other words that can be used for correction include:  Quiet, Leave It, Drop it, Stop and Off.  However, despite what words you may use, be sure to use them sparingly and only when you need them so they will continue to have strong meaning to your dog.  When given, a reprimand should be short, direct and immediate.  Also, when you say these words your tone should be firm and even harsh if necessary. 

Don't ever feel guilty for disciplining your four legged friend.   This is part and parcel to his learning and development.   By allowing him to get away with unwanted traits and actions you are not doing him any favors.  He looks to you for guidance, so don't be afraid to be a true leader and lay down the law, because in the wild the alpha of the pack wouldn't sit back and let his pack mates do as they please.