Okay, what you need to do to get your horses soft and supple and rounded is 1st, you need to work on flexing exercises. Clinton Anderson has some articles on his website explaining the training process to get them to do it. Personally, what I had to do to get my mare to stop spinning around in circles and just stand still and flex from side to side was to go right up next to the fence. To bend to the right, have the fence on your left. A lot of people think that he's too harsh in his training methods. I personally don't think so. I think that at least the concept he explains is to be firm, but kind, and to get the horse focused on being respectful to you.
Back to the flexing. Start with the side to side, and get him to do it from a stand still all the way up to a lope. Then start with the 'vertical flexion.' This is flexing at the poll. What I did to teach my mare this was to get her going forward, ask her to bend her nose towards me, when she did it, hold it for a few seconds, then let her go. Letting them go is their reward, get it? Then I found CA's method. Either way would work. Again, try it from a stand still all the way to a walk. I try to keep this cue to flex at the poll separate from teh cue to put her head down. Which, using a shank bit, is to pick up on the reins and bump gently. At first they'll pick their heads up, and the higher they go the harder you bump, and the instant they put their head down, even the slightest bit, you let go. This is also a good soft-mouth exercise.
Once he knows flexing, start playing with it. A circle here, a circle there, back a few circles here and there. Keep in mind anything that flexes him will help him soften. I don't think a hard mouth has really anything to do with it as that the horse is either stiff or he just doesn't want to do what you want. There are horses with more SENSITIVE mouths, like some people who don't like to bite into cold things while other people can, but that's something different. Since you want him to do reining and western pleasure, it's important that he keeps his head in and his nose tipped toward his chest, just don't overdo it.
Now to get your horse off it's front end, here's what you can do: get him going forward, go a few steps, then stop and back him up. Do this for awhile, but be careful not to stop in the same place to many times in a row, cause then they'll start to anticipate.
NOW you can start getting your horse to round up his back (collection). Take the vertical flexion (be warned you're going to use your feet for this too) get your horse going forward at the walk, and while you're walking, ask him to do it. AT THE SAME TIME GENTLY bump him in the belly with your heels. You don't have to use your spurs.You will feel him round up. You'll know because his head will be low and rounded and he'll have an even pace. If you need to get an experienced person to watch. He can tell you when he's rounded and eventually you'll get to where you can feel it.
I hope this helps. Good luck! It's pretty cool that a young horse beat all the older ones, LOL!
Mae
If a horse has four legs, and I am riding it, I think I can win. - Angel Cordero Jr.