I started breaking horses to ride and drive when I was 12. By the time I was in my 20's I had developed a penchant for re-schooling anything that would turn the men in my county ashen at the mere mention of "that horse" and it's why I'm in the shape I'm in today
They're all different, they all require getting to know who they are. When working with my granddad's horses, I knew who they were from birth. They got handled every single day by my cousin and myself.
They were broke to a driving bit and long-lined way before they had a riding bit in their mouth. They were broke to a saddle when they were yearlings but we didn't ride them, even though back then we were tiny enough to do that.
We taught them nearly everything from the ground since there's a lot of days between birth and two years, when our small youthful selves would finally get on their backs.
They all knew how to "whoa" "go", neck rein, back up before we ever got on them. We jumped logs together, side-by-side. Grandad kept us girls pretty skinny teaching all that stuff to the young ones, up and down the mile long tractor lane, crossing the creek, negotiating between trees
Granddad had a waiting list for his Welsh/Morgan crosses as they were broke by kids. It was nothing for him to get $300 - $500 for a long two year old back in the early/mid 60's. Quite a bit of money back then, especially when there weren't any papers but he had a good reputation in our area
The Widowmakers in my life were another matter. Most often they were hiding who they really were as a result of either abuse or just plain ignorance on the part of previous human(s) and the horse was ill-tempered and allowed to get away with everything.
While I handled them every day, it was never a rigid form of work until I could figure out what it was going to take to get them to respond to me in a positive way. Some of the ruined horses took a lot longer to learn trust than others; some of them dumped me on the ground a few times before I finally won that war.
Once the trust was there and I knew the horse had a good "whoa" and a "go", I called some friends, we loaded up and went trail riding since the best way to get a trail horse "sensible" is to stick them on the end of the ride. At least that's how we always did it and with great success.
So, the basic answer to the OP's question is I break a horse according to what the horse tells me it's ready to do. I am not a professional and never desired to be. Therefore time is not money and the horse can progress as it's ready; again some faster than others and yet another reason to take invite a seasoned trail horse along if the horse being re-schooled has some big issues.
Since I am strictly a trail rider, I have no need to push a horse hard; I nudge them along and was always fortunate to have another horse along to help with the nudging
Even though I miss it, I have long-since retired from all that excitement. My current four are my last four. I handle them every day and they are broke to death. Unfortunate circumstances caused me to not ride any of them for nearly three years. The day I got back on all of them and took them, bareback, down the road, they went like they'd been ridden every day and that is because they are handled in a positive way every day. They aren't turned out in a field 24/7 with no human contact until I want something from them.
Horse-handling is a two way bridle path - you get what you give:)