I train my horse according the Bent Branderup method/Academic Riding Art. He is from Denmark.
You start to bend the horse standing, then in walk on the volte. The horse is lead by a cavesson (no bit) and the main purposes in the start of the training is:
Head lowered (to strech the back and make the underline (belly) muscles strong)
Looking in the right direction
Stepping under the body mass with the inner hind leg (under bellybutton)
You start training in walk and on a circle. You walk next to the horses head.
Here is one short movie with the results of that particular method:
THis is her channal on You Tube PaardenBegrijpen - YouTube
I knwo there are also movies about starting the horse this method.
Her website is only in Dutch, but her movies are in English. If you have any questions, let me know.