Quote Originally Posted by GraceByDesign

Place the collar or loop directly behind the dogs head, not down on her neck. It will probably sit just behind her ears. Think of dog shows, where the loop of the lead is placed up close to the head. (info found in the book Cesar's Way) (ETA: not a direct quote)

I placed her collar as advised, and kept a short firm lead (not tight, but not slack - again, like a show dog). She held herself much more proudly and just fell into place and trotted along side me. No pulling at all. No choking either. It was amazing!! I chose the right side, as I am right handed, and know nothing about right or left for 'heel'. That was all I did. I did not say anything to her, nor did I give her treats. I praise her occasionally. And walks became enjoyable, instead of struggles of will. We also practice sitting at intersections and at other times on our walks. I praise her for good sitting.

HTH

I have to agree, because I think the first thing you need to get across
to a full grown Boxer, is that you control the dog's movements and not the
other way around. Your first aim(with a strong breed) is to gain control on
the walk. Once a dog understands you are the "director", the leash can be
loosened for a more casual style of walking.