The biggest problem I have seen with loose leash walking is consistency. You can see it easily by looking out your window. Dog pulls, person corrects... dog pulls, person corrects... dog pulls, person corrects... dog pulls, person gets annoyed, and lets the dog pull. You have to correct the behavior every single time, without fail, and you have to reward the behavior you want, every single time without fail. If you are not 100% consistent, you are teaching your dog one thing. Sometimes he's allowed to pull, sometimes he's not. What most people also don't realize is when a dog pulls, it creates tension, and the tension will cause the dog to pull more. So, you want to never get to that point. I find the turn around and go the other way method has worked on just about every dog I have ever tried it on. Pick a point that you're comfortable with, and every time the dog passes that point, give a "no" and go the other way. Reward your dog for being behind the imaginary line. Where the line is is up to you. I don't expect a formal heel on a walk, and I don't mind my dog being a little ahead of me, but I don't want her determining where we go either. I take the lead, loop it on my hand, and wrap it around my hand a few times (I want to preface this with my dog is full grown at about 32 pounds. I would never wrap a lead around your hand with a full grown doberman, because it's asking for trouble. While I would call Dakota pretty strong for her size, if I trip, there's no way she's going to drag me down the road on my face. A shorter lead would work better for bigger dogs.) so that she can only go a certain distance. I may let out 3 or 4 feet of lead. As soon as it gets tight, "no", go the other way. If you don't leave your front lawn for a week, then so be it. But if your dog pulls, and you keep walking, you're reinforcing the behavior, and it will simply never stop. It's best to nip this in the bud while your dog is young, and you are stronger than your dog. A full grown, powerful doberman pulling at the end of a leash is not going to be fun. So do it while they are more manageable, and while they're young it's easier to teach good habits.
I don't recommend harsh corrections, head harnesses, or other "tools" to stop pulling unless you really know what you're doing with them. We have to remember that these are tools to be used along with TRAINING. If you put a prong collar on your dog, and your dog stops pulling, it doesn't mean he's not going to pull in a different collar. You still have to incorporate the training, so that your dog is actually learning not to pull, as opposed to not pulling simply to avoid an aversive. (correction)
So, to sum it up, if your dog goes past where you are comfortable, "no", turn around and go the other way. Every...single...time.... If your dog is walking next to you, reward, every...single time... Quickly at first. If your dog is next to you, immediately reward. Take a few steps, immediately reward. Repeat this. The more you reward, the more your dog will walk next to you. Make sure you are using high value rewards. Then proceed like any other behavior. Once your dog is understanding where you want him to walk, you can start rewarding less. Instead of every step or 2, start rewarding for 10 feet, or 20 feet of good walking. Then keep weening, until you are at the point where you no longer have to reward during walks, but you can reward when you get home for a good walk. How fast you ween off depends on the dog, but remember that you don't want a dog that is ONLY walking well for the reward. This is why it's important to ween off, because you don't want to build a dog that won't listen when you don't have a reward handy.