Make sure you're a reliable "alpha" and the rest w
Are you a confident, calm leader?
Are your rules consistent and clear (to the puppy)?
Do you bear in mind that human language has no inherent meaning to your puppy (that is - "good puppy" and "OMG, you little sh*thead", if spoken in the same tone of voice, are identical to him), so that each word or phrase he learns is a major achievement?
Do you recognize and reward correct behaviors, or only respond to (and punish) incorrect ones?
Do you give him a good reason to behave well (that is - if he does something right, does he get something good, be it treats, dinner, play, loving attention, etc)?
If you correct inappropriate behavior, does your correction relate (in the puppy's brain) to the bad behavior; and is it an appropriate level of response (that is - if he's 16 weeks old and mouthing, do you fly off the handle as though he was 2 years old and bit you in the a$$)?
All this being said, I do not ascribe to the opinion that dogs in households are constantly on the lookout for ways to move "up the ladder" and challenge my leadership. The "alpha" studies most often cited focused on behavior within wild wolfpacks and are years out of date; it's a mighty big stretch to assume they apply to cross-species interactions between domestic dogs and humans. My experience, limited though it may be, has shown me that dogs whose owners are dominant without being domineering, lead through calm, consistent, positive methods, and restrict "corrections" for limited situations when they are essential and immediately applicable, end up with the best-trained (and happiest) dogs. YMMV.