Disclaimer: I am not the dog whisperer, nor do I claim to be an expert trainer or to have methods that are the be all end all of training. These are simple tricks taught to me by more experienced obedience instructors, and as an instructor myself, I like to pass on what I've learned to others. It can always benefit SOMEBODY right (and how about we don't fight about the methodology, k)?
Teaching your puppy to heel:
This one's pretty simple. Some people do it on lead, some off, but the key here is you DO NOT correct your puppy! Correcting your dog for something it doesn't know is incredibly unfair, and they can end up REALLY confused!
Taking the leash in your RIGHT hand and a cookie in your LEFT hand, hold the cookie in front of the puppies nose and walk. Do not walk too much...2-4 steps and that is it. Allow the puppy to nibble as it walks. If the puppy is bouncing while you are walking, you're holding the treat too high.
If you have a bad back, take a dowel or wooden spoon and dip it in peanut butter or spray it with that spray cheese. Allow puppy to lick and walk. While the puppy is not looking at you, it IS learning to keep its head up, which is the start of "watch me"
For those who do not know, heel is NOT an action!! Heel is a POSITION! "Heel" is between the tip of the dogs ear and the dogs shoulder blade, and the dog should be aligned with your hip. In the end, when you tell your dog to "heel" you are telling your dog to keep in position, not perform a true action (clear as mud right?).
Teaching/proofing your puppy to find heel:
Most people think their dog knows where heel is. Most people are wrong. To check to see if your dog knows where heel is, take a couple steps away from them (back to them), and call them to heel. Many dogs will walk right on by the handler and look at them like "What?" because the handler taught heel as an action, and not a position. Can't tell a lie...my own dog did this and I had to go back and retrain it.
To help your dog find heel, take a cookie in your left hand. Keep both hands down at your sides and call your dog to heel. With your cookie hand facing the dog (palm toward the dog), when the dog is in position and it sits, give it the cookie. The dog should not go beyond the cookie hand (likely it will be trying to get at the cookie so it can't fail), and you can remind the dog to sit if need be.
Do this in straight lines at first. Eventually, start putting obstacles in the way that they must go around, through, or over to find heel. It's really neat watching them catch on
Quarter turns:
This is a way to perfect both right and left turns as well as help the dog find heel position. It is exactly as it sounds. With the dog starting in heel position, announce "Dog heel" and take a slight step forward as you turn (step back for left quarter turns). This will start teaching the dog to get up and move with you in heel position. As the dog gets better at this, simply turn it into a pivot and turn in place.
When teaching the dog the left turns, give them a different command. It helps them differentiate between backing up and following. My dog responds to "Zuruck" (Get back) but he knows it means get back and STAY in heel position. Initially you may need to "pop" the dog back to get him to swing his butt back around. It's NOT easy! You can use a cookie lure as well.
Circle left/right:
Just like it sounds. Do tight circles to the left and continue on your way, and tight circles to the right and continue on your way
Back up:
This is one of those things that REALLY helps teach your dog where his butt is! Stand in front of him with cookies in your hand. Present the cookies to the dog so he can nibble and very slowly start moving forward. If your dog backs up two or three steps, "WHOO HOO! GOOD DOG!" and you give a cookie

Eventually you can do what Strauss and I do. I walk into him and tell him "back" and he keeps back up as I advance until I tell him to stop.
If I want him to back up and have myself remain stationary, I raise my hand and tell him "Zuruck!" and I keep telling him "Zuruck" at random intervals until I'm satisfied with his distance.
Get over/get in:
If you're in a trial and your dog isn't set up properly, it takes a LOT of time to walk in circles and what not to get your dog in heel position. Teach your dog to "get over" and "get in". To teach "get over" (I don't say "get out" because that's an agility command for me), I simply side step left into my dog and say "get over". He doesn't want to be stepped on, so he moves. When he moves over, he gets a cookie.
Get in can be harder to teach because the dog will put his front "in" but not his rear. Using a cookie lure, take a small step to the right, give a LIGHT pop (a tug) on the lead, and tell the dog to "get in". He should follow. Even if it's only a LITTLE bit, the dog complied. Things will get better as you practice.
Bleh, longer than I intended, but perhaps this will help some who are having trouble with heeling or who haven't tried some of these things for improving their heel work.