The dog is measured against the standard for the breed by different judges. While there is no "perfect" dog, the goal of breeders is to produce dogs that come as close as possible. Proportions and structure, head, neck, movement, balance, coat, temperament, and type are considered.   Winners dog and winners bitch receive points towards their championships. 

Puppyhood is an ideal time to begin training for the conformation ring.  Condition your puppy by running your hand over his back and down his legs several times a week.   If your puppy is a male, touch his testicles so that he will be used to having that done. Go over the tail.   Dogs often do not like to have their tails handled.  Lift the lips to look your pup's bite often and gently.  Tell him "teeth" or whatever you like.   Get your puppy used to being handled-  all over. But do so gradually, a little bit at a time.

Lure the puppy into a stand position by holding a treat in front of his nose.  Let him nibble on the treat as you say "stand."  Simultaneously move the treat slightly out in front of the pup, walking him into a stand position.  Happy talk.  Release him with an "okay" and let play. Keep these sessions short and playful.  In time, your puppy will begin to stand happily on your command.  Think of a special command for these "games" such as "showdog."

Your puppy should be leash trained.   Get him used to walking on your left side.  As your puppy gets older, you can trot him on your left side for short distances.  Teach him to stand as you gait up to a person.  Have the person give him a treat.  This will condition the pup to look expectantly at the judge thinking there will be a treat.  Clicker techniques are good for such things as getting the ears up, stacking, coming up to the judge, as well as a multitude of other behaviors.

Prior to showing the dog, some conformation classes or private instruction are very helpful.  The early conditioning you did on your puppy will serve you well at this time.  When you do take your dog out into the conformation ring, do so with a happy, fun attitude so that the dog will think such outings are great fun.  And, by the way, all the other owners in the ring feel a bit nervous too!