Lungeing from the bridle offers different challenges than using a halter or lungeing cavesson. Connecting a lunge line directly to the bridle should only be done with a well-schooled horse that you have worked with before. An inexperienced horse may jerk its head and inadvertently pull the bit through its mouth. When using this method to lunge your horse, use a snaffle bit with large rings. Be sure to either unattach or tie up the reins so they do not get tangled in the lunge line or fall off the horse and get stepped on.
Bridle your horse with a snaffle bit.
Stand facing the side of your horse's head.
Thread the end of the lunge line with the clip on it through the bit ring.
Pull the line gently up the side of the horse's head and over the top of the poll. The poll is at the top of the head directly behind the ears.
Move to the other side of the horse while holding the line in place at the top of the poll.
Face the side of the horse's head.
Pull the line down the side of the head and clip it to the bit ring.
Unsnap and reattach to the lunge line in accordance to the direction that you will be working from. The side of the horse that you originally stood on will be the side you work from.
This is a technique best used by experienced horse trainers.
Unsecured reins are a hazard. Do not jerk the horse's head or mouth.