Riding Exercise #14: Yield the Hindquarters & Back Up Goal: To have the horse soften his head and neck laterally, yield his hindquarters 360 degrees, and then back up. The horse should move backwards energetically with no resistance in your hands. More about the exercise: https://www.downunderhorsemanship.com/Store/Product/MEDIA/D/252/
Groundwork Exercise #8: Outback Exercise Goal: To be able to back the horse away from you in a perfectly straight line without ever having to move your feet. Then you should be able to draw him back up to you by gently combing the lead rope through your hand. More about the exercise: https://www.downunderhorsemanship.com/Store/Product/MEDIA/D/253/
Learn This Four-Pole Exercise. Use just four 12-foot poles to lengthen your horse's stride, improved his focus, and guide, and hone your control. - See more at: http://horseandrider.com/article/fourpole-training-15871#sthash.0sfPh3Is.dpuf
It's very normal for young horses to mouth and play with the bit. They're just trying to figure out what the new piece of equipment is. When I put a bit in a horse's mouth for the first time, I like to practice groundwork with the mecate bridle so the horse gets used to feeling the bit in his mouth, and at the same time I'm getting him to use the thinking side of his brain by moving his feet. That way, before I get in the saddle and pick up on the reins, he already knows how to respond.
Exercise #20: Laying the Colt Down Goal: To be able to lay the colt down with no resistance using a lariat. Then while the colt is on the ground, to be able to rub all over his body with your hands and desensitize him with your tools while he remains relaxed. https://www.downunderhorsemanship.com/Store/Product/MEDIA/D/2896/