Step 1: Heirarchy - a puppies place
Eat before your dog and dont ever feed the dog while you are eating.
When out walking do NOT let the dog walk in front of you. A dog walking in front is a leader. The leader should be you.
Do not let your dog get their food until you say so. Teach your dog "wait" (i will expplain how in this instructable)
If your dog watches you eat, growl at the dog. Yes growl. You might look stupid, but the dog will soon learn to stay away from you while you eat, like they would in the wild.
Credit to mrmath for this v
Best way to become alpha dog, and I've used this on huskies with serious alpha dog issues: make eye contact, and make them look away. Eye contact is big for dogs. Stare at them. Right in the eyes. Don't look away until they do, and only after they do.