The bridle is an invention that is used to communicate with your horse and to help to lead it in the correct direction. It's depressing to say that some people over abuse the bridle. An example of over abuse of the bridle is yanking on the reins which it connected to the bit in the horses mouth. How would you like it if someone started yanking on your mouth and you having no idea what to nor whats happening. Here's an experiment, put one finger in both sides of your mouth and pull back as hard as you can. That's how horses feel when you tank on the reins. Although some people don't yank on the reins to hurt the horse, it's simply just out of fear. Even if you just tighten on the reins fearfully. Horses feel your fear and get there energy off of your emotions. So most of the time if you're scare your horse is going to think there's danger and act up. Although not all horses are jumpy, like school horses, and they stay calm no matter what you do. Relax may be the first thing that comes to your mind when you mount your horse. I know that's the first thing that comes to my mind still and I've been riding for a good amount of time.
The previous paragraph was all the don'ts of riding with using your bridle. Now here is a easy list of do's with your riding aid. When using the western bridle, you want to keep a really loose rein. Not so loose if your horse freaks you can' control him/her, but loose so you're not choking your horse. Western is, most of the time, a relaxed sport unlike English riding. When riding English, you have short reins, but just because they have short reins does not mean you choke up on your horse. Keep a firm, not tight, grip on the reins and proceed with the actions. You're probably wondering, 'all this talk about reins and hands, is that all you have to do in riding.' And that is absolutely wrong. In horseback riding, any discipline, your legs are also doing work. Its about 75% work with your legs and heels. In dressage you have to send correct signals to get your horse to perform the right move. In western you have to use your inner legs to round your horse's body while maybe doing pole bending. In jumping you have to urge your horse to go forward. There are a lot of aids you have to use to become a good rider.