I’ve been looking through the workout history of some recent purchases, and I noticed something: sometimes the jockey’s compatibility with the horse can go from “X and I don’t get along at all” and change through time if you just assign the jock and let workouts run. Is this actually what people are doing to get the right jockey for the horse? Because I’ve always had trouble figuring out jockey/equipment etc for my horses 
It can certainly work. You may see it more with young/green horses since the newbies can be hotheads. It can be a toss-up whether or not they grow to like each other, but one thing you can be fairly sure of is that you will at least have one jockey early on who knows the horse pretty well and who can potentially give you feedback for equipment and run style.
Personally, I like cycling through jockeys early on to see who gets along with whom from the offset. It also gives the different jockeys experience with the horses in case I don’t get my pick of jockey in a particular race.
Once I find a jockey who gets along with the horse, though, I train solely with that jockey till they know the horse like the back of their hand and have given me good feedback for running style and equipment. Then I start looking for a “second” using the same method.
Dunno if my way is terribly efficient, but it seems to have worked well for me so far.
That makes sense, seems like a smart way to do it. I think the main issue I’ve been having is training consistently–if I can’t get a workout in almost every day, it will take a long time before I can find the right jockey for a horse, and what with race entries etc it’s pretty inconsistent. I was thinking it might be better to pick a jockey who has ridden the horse a few times and just keep them on board for a month or two straight, just to see what happens?
I’ll experiment with it 
I use the auto-workouts which keep training consistent. If I enter a horse in a race and there is no dedicated jockey for it, I leave that slot open unless the horse has run decently well under a particular jockey before.
Really, it’s largely a matter of trial and error, what works best for you and your horses. Good luck!