Make sure your commands are consistent: what you say "NO" to one day must not be allowed the next, either by you or anyone else in the family.

From the very beginning, you need to make sure your puppy understands the word 'NO"

• "NO" needs to be associated with anything forbidden, whatever it is.
• "NO" must be totally categorical, and be said very clearly whenever  you see your dog do something he shouldn't.
• The tone of  your voice should be sharp enough to make the puppy stop as soon as you say "NO"