If you only use your hands when putting your horse on the bit, you’re making one of the biggest mistakes you can make. By focusing on the head and “getting the head down”, you’ll just be creating an artificial “head-set”. Putting your horse on the bit has nothing to do with “head sets”.
Physically, when your horse is on the bit, he has a round silhouette that only occurs when you ride him from behind, over his back, through his neck, and into your hands. (And at that point the energy can be recycled back to the hind legs)
Mentally, a horse that is on the bit is “on the aids” and anything (like a transition, extension, or stepping into a lateral exercise) is possible within the next step.
When you’re working on putting your horse on the bit, remember to always FIRST use your driving aids before you use your reins. You want to create a surge from behind as if you’re starting a lengthening.
Then just as you feel your horse begin to lengthen, close your outside hand in a fist to capture, contain, and recycle that power back to the hind legs. (You’ll only need to use your inside hand if your horse bends his neck to the outside during the combination of the driving aids and rein of opposition (outside rein).
Maintain this marriage of driving aids, bending aids, and outside rein for approximately 3 seconds.
Always remember that using your hands BEFORE your driving aids (or instead of your driving aids-YIKES!) is the same as picking up the telephone before it rings. Why would you pick up the phone? No one is there!
By the same token why would you use your hands to put your horse on the bit before you’ve first driven him forward? You haven’t created any power to capture and recycle back to the hind legs!