How to Put a Bridle on a Horse

Pull the Crown Over the Right Ear
Switch your grasp of the crown of the bridle to your right hand, and with your left, gently slip the left ear under the crown. Do not pull the bridle too high; this action pulls on the horse's mouth. Be careful not to bend your horse's ears uncomfortably.
Fasten All the Buckles or Snaps
Fasten the throat latch of the bridle. An endurance bridle has a snap at the throat latch. Most traditional leather bridles will have buckles. Do not fasten the throat latch too tightly; you want your horse to be able to flex its neck. Leave about 4 inches of slack. You should be able to slip the width of your hand between the strap and your horse’s jaw.
Unless you use a special noseband, such as a figure-eight, flash, or grackle noseband, leave about two fingers width between the lower jaw and the strap when you attach the noseband or cavesson. If you are using a curb bit,
 
you’ll need to fasten the curb chain or strap. Leave the width of two fingers between the chain and the lower jaw. Leaving the chain too loose or tight can make the action of the bit or the chain more severe. If the bit has a port, it could rotate up and hurt the top of the horse’s mouth.
Slip the halter off, tidy your horse's mane and forelock, and you are ready to go. Some people like the forelock under the browband; some leave it over the top.
Removing the Bridle
Remove the bridle by slipping the halter (attached to a crosstie or lead rope) back over the horse's ears. Undo the throat latch, curb chain, and noseband. With your left hand, reach under the horse's neck and slide the crown over the horse's ears. Hold it as you did when you were putting it on. Gently lower the bit out of the horse's mouth. Be careful not to knock the horse's teeth. With your right hand, slip the halter on and pull the reins up over the horse's neck to completely remove the bridle. Once you remove it, you may wish to clean your bridle or wipe the bit before hanging it away.