Whenever I get a new horse in, I've always given them time to settle in before "real" training begins. This doesn't mean I do nothing to them though. I start by touching them. In the pasture. However and where ever I want. Mango was the worst at this with the bunch of horses I got this year. It may sound odd, but just like my dogs, I want them to learn that training can happen anytime, anywhere. There is never a really true "off" time. Granted they get to spend most of their time doing whatever they want, how they want, and when they want so I have little sympathy.
So much like my other horses I've trained, I spent time in the pasture to start with. For my sanity, I left a halter on Arthur since he had shown he could be a turd about being caught or basically anytime he didn't want to have a person around him (which was most always). I normally start out while feeding since this can be the most dangerous time as the horse WANTS what you have and most horses have TERRIBLE feeding manners. I just touch their shoulder with a flat palm or whatever (no poking) and then I dump the feed. When they start eating, I touch their shoulder or neck again. Most new horses will pin their ears back or something similar and I'll snort and throw my hands up and chase them away from the food.
I'll repeat this until they stop the behavior. Less ambitious horses will sigh and I'll walk off.
This is the start of all things they hate. Might as well get it going, right? The other thing I start doing is following them. This is a bit like what Monty Roberts used to talk about in his early books. I have no idea what he does now with his training but when I want to single a horse out (basics of catching them), I follow them. They move I move. They stop I pause. Most new horses hate this and will run around like idiots. I just keep following. Its REALLY fun to watch my older horses in the pasture, you can basically see them shaking their heads at the newbie.
So Arthur hated all this, he took his big sexy self and floated around my pasture arrogantly. My pasture is divided into two larger portions connected by a long 20 foot wide "chute" area. I patiently cut the other horses to one side of my body and him to the other as I stood in the chute. He charged me. I convincingly drove him away with the lead rope and he darted back to his side of the pasture. This took about an hour, but he finally sighed and just stared at me as though wondering what my deal was and why I hadn't given up. I walked over, lead rope in hand and pet him. Then I left. This is when they normally go "WTF" and I like leaving them with that thought. It means they are thinking so +1 there.
Most people are so quick to snag the halter and that's not the point. Your horse should accept your presence and wait for you to make the move. Grabbing a halter as your first move doesn't show trust or confidence at all on your part.
The next day he was less apt to run. I calmly touched him then his halter and then began touching his forehead. One pat = one release. We continued this twice a day for about a week. Once I got to the point where I could rub his face and he was seemingly happy/accepting about it, I worked on moving north and onto his ears. He was fine with that for about as long as it would take to put a bridle on. When I lingered longer one morning, he reared up and tried to drag me. I let go and commenced following him around. Recapture, retry, recapture, retry. This went on for about an hour before I could even put one finger near the base of his ear.
We had something concrete to work on.
When I got Arthur I knew that accepting and understanding pressure was going to be his "thing." He's a kind boy and VERY smart so I knew patience and just "messing" with him was going to be the way. The hard part on a horse like this is you first have to "break" him. Not by spirit, but his old habits. Everything he did, he was good for the "normal" amount of time. Come up with a lead rope? He'd stand long enough for you to clip it on. If you didn't directly do that, he'd arrogantly charge off like he'd won a prize. Touch his ears? Only long enough for a bridle. "No sightseeing here please!" he was screaming. Petting was something he simply accepted and then shut down about. Get pushed? Shut down. This lack of coping skills meant that at some point he'd blow. And that was why he was considered "unpredictable" and such a dangerous horse.
I had to break all this up like an ice flow in Greenland. I think Greenland has ice flows...
To effectively do this however, you have to be systematic about it. Build trust, then push it. Build trust, then push it. Push, pull. That's about all there is with horses. And patience. Patience of a saint helps. You cannot get emotionally involved either. Rebuild when you need and always have a plan. And always ALWAYS be willing to temporarily change that plan to help the horse understand the goals. Keep pushing... Keep building... Rebuild if need be.
So every day we touched and I pushed him a little further. Touching near his ear in the pasture moved on to touching an ear. Then the other ear. Then petting the ears back then holding my hand on them. Then petting them forward. Then back. Then I began rotating and manipulating them in my hands for as long as I pleased. An accompanying exercise I was working on, was yielding to poll pressure. I never did both exercises at once in the beginning. I either did poll pressure OR the petting. If his head went up even a fraction with poll pressure, I asked him to lower it a fraction until he did. Once he was good with both pieces, I started putting them together. Lower the head, touch the ears. Lower the head, touch the ears. Soon his head was on the ground and he was ok with his ears being inspected. This was the point where the two exercises had effectively come together.
This was basically our first two - three weeks. No lead rope, no leading, not even leaving the pasture. I like to work my horses around the other better trained horses so they get used to distractions like that from the start.