According To H.T.

After you have gotten your horse familiar with the bit, I would now introduce the saddle. If you have done all the preparation for this you should not have any trouble. When you put the saddle on for the first time, you do not want to tighten the cinch very tight. Just enough so that it stays on then send your horse out on the rail. Let him move around the pen with the saddle for a few minutes, call him back, tighten the cinch a little more and send him back on the rail for another minute or two. Continue doing this until you have the saddle tight enough that you feel comfortable mounting.

Before you start to mount the horse, take your lariat or stick and rub all over the horse, under his belly and down his legs. This is a very soothing thing for your horse and just a way of telling him everything is OK. Move through the exercises you have been working with him on now. Such as stepping over with his front feet and then stepping over with his back. Ask him to back up, then circle you by holding him close with the reins. Do all of this from both sides. With the lead over your left arm and the reins over his neck start slapping the stirrup leathers making a popping noise. Pull on the stirrups and have them gently hitting the sides of the horse. If he is not happy with this you need to send him back on the rail so that he continues to get used to the saddle moving around on his back. If he is OK with all of this, then you can feel comfortable mounting. Turn the stirrup so that the opening is facing you. Place your foot in the stirrup and begin putting pressure in it, just a little at first, more of a bounce. Again, if he is not happy with you doing this or moves around, send him back on the rail. We want the horse to be more comfortable with you and what you are doing than he is running around the pen. When you think he is ready to listen, call him back and try it again. Move to the other side and do the same thing. When he stands perfectly still, start straighting your leg out... putting all your weight in the stirrup. Still do not mount, but stand in the stirrup for a few seconds, come down and reassure the horse that this is all you want. Be sure and do this on both sides until you and your horse are comfortable. You will know when it is OK to swing your leg across and mount. Again, only for a few seconds and then dismount. Be prepared to use your leg muscles on this day, because it is a lot of repetition.