What's your leash-handling style?

The leash may be the most commonly used and misused dog training tool.

There is no leash
The owner acts as if the leash does not exist, using the exact same commands, feedback, and rewards s/he would use if the dog were loose.  The leash's only function is to stop the dog from running off.  While more challenging for the owner to teach, this style facilitates transition to off-leash responses.

Jockey-style
The owner uses the leash as a rider would rein a horse, using pressure on the dog in various locations (top of the neck, bottom of the neck, left side of the neck, ride side of the neck) to cue the dog to move in various directions.  The dog must be trained to respond to these cues, exactly as they need to be trained to respond to SIT, DOWN, COME, HEEL, and other commands.  Shaping or luring are great ways to teach the responses you want.

Handle
The owner does an impression of a waterskier behind a very large, excited dog.  This practice offers almost no ability to influence the dog's behavior, except for slowing his gallop.  It also offers onlookers a great show.  The owner tends to focus most of his/her energy on remaining upright, and on the same side of trees and street signs as the dog, typically with marginal success.

Punisher
(Training collars can be used effectively and humanely, but such use cannot be taught by text, so I won't try.)  The Punisher is a variation of the Handle where the display is occasionally interrupted with a human yankfest, as if having some kind of fit.  This fit is intended to display to other humans, "I am attempting to control a beast who is clearly uncontrollable," but says to knowledgeable humans (and also the dog) "Hey, I have no clue what I'm doing!"