If you simply wish to position your dog correctly and then have him hold that position, the 'Placement' method will be the simplest method to use. If you wish for him to look as though he effortlessly chose that position without your assistance, then the 'Lure' method or the 'Capture' method will work best. Expect both of these methods to take a bit longer to train though. Also be aware that the 'Capture' method does not work well for all dogs because not all dogs naturally offer the correct stance occasionally when they stop walking. If your pup does offer the correct position at times when you stop moving, then this method might work wonderfully for you though.
If you are using the 'Lure' method, then when you get ready to teach Fido where to shift his weight, be aware that moving the treat to fast or too far forward or backward will cause him to move out of position entirely. There is typically a wonderful middle ground, where you can make minor adjustments to his stance without changing his entire position completely. For this reason, keep the movements slow and small.