Pulling on the lead
It is natural for your dog to want to walk ahead of you: you are his companion and he probably wants to walk faster than you or maybe he wants to lead. This can place him in danger and it can certainly make your walks uncomfortable!
Below I will list a few ways to help your walks comfortable again.
Treat Training
Start with the basics, work with him as if he was a pup. Hold a tasty piece of chicken in your hand and put it down by your side with hand flat out, start walking forward and once your dog touches your hand with his nose (being behind you and in heel position) let him have the treat, repeat this process ten times. Then introduce the work ‘heel’. Wait until he noses your hand say ‘heel’ (in very happy voice) and then give him the treat. Repeat this process for at least a day before removing the treat from your hand and only giving it to him once he has nosed your empty flat hand. You will have to repeat this process for a few more day before you can gradually remove your hand and just be able to give the command ‘heel’.
If you prefer just to have a ‘loose lead’ walk with your dog please refer to the 'Puppy Manners' article.
Halti

Halti works best if used with a long lead of minimum 1 meter. You can transfer a gentle tug via the Halti to the dog’s head, and thereby initiating a slow down or ‘heel’ response.
Overtake your dog as he slows down, and when your knees pass his head praise him with “heel”. If he is Clicker trained, click. The preferred zone in which your dog walks is then 30-50cm in front of your knees. Moving ahead brings the likelihood of pressure on the lead via the Halti.
If your dog is very clever, he may learn to defeat the Halti principle by stiffening his neck muscles, making the whole spinal column from head to tail like a stiff cylinder. The way to beat that cunning canine manoeuvre is to step to one side and guide him sideways. Halti is the one of the best headcollars because it sits further down the dog’s nose than other designs. This gives increased turning power to you. So if your dog pulls on his Halti, step to one side and turn him sideways, even in a complete circle.
Easy Walk Harness

This momentarily alters the balance of the dog to gently get the dog’s attention, stop pulling, and look around in surprise at the handler.
This can be accomplished because the leash attachment at the front of the harness is designed to slide slightly to one side or the other.
The Easy Walk Harness is designed to gently discourage your dog from pulling while walking on a leash. And, it's easy to use, requiring virtually no acclimation period or specialized training.
Illusion Collar

I'm not sure if these are available in the UK yet however are proving popular in the US.
I do not have a lot of information on these collars, however I am lead to believe it gives you more control over the dog as it uses a more sensative part of the neck (the top) and the dog is less likely to pull. If you have any further information please Contact Us
Half Check training
If you own a strong or large breed, then this training may be the one for you. Half check collars are half normal collar and part chain.

You connect your lead onto the hoop as normal and basically the collar will tighten if the dog pulls to hard, but this is a much safer method than choke chains where the dog will possibly choke itself to death. You will find lot of large breed owners use this method, as unlike with a small dog you cannot stop an 8 stone Rottie as easily.
When setting off for a walk raise the collar up to just at the base of your dogs ears. This is the most sensitive part of your dogs’ neck which will make him less likely to pull. Once in the correct position, clip the lead to the loop and hold the lead on one hand above your dogs head, you will have total control from this angle. Whilst out on your walk encourage your dog by verbally praising him, keep saying ‘heel’ in a nice friendly high pitched voice, if he does try and venture forward, or the lead slips down, think of a good noise that will let him know that behaviour is not acceptable, we like to use “ah!” short, sharp and low. Then have him sit down, adjust the collar and carry on. Do this training in short sharp bursts, try and take at least 20 steps before getting your dog to sit beside you then give him a big rub all over and praise him lots! Start walking again for little longer this time, then get him to sit and give him lots of attention!
Also add some variety into your walk, dogs find human pace extremely boring, so try to run with your dog, do some weaves, then slow it right down almost to creeping pace and then run around again, all of this will teach your dog to watch what YOU are doing and will make them more likely to stay by your side. Do not attempt to add any distractions at this stage until your dog is comfortable with this style of walking. This is a slow process and will take high level of patience, if you are in a bad mood or tired please do not attempt to train heel work with your dog.
If you have access to places you can let your dog off lead I would highly advise you tire your dog out before attempting any heel-work training.
Written by Nats