Patience and practice -gee, just like riding a horse! I’d take some cones out to a big parking lot and make sure my turn radius was what I expect. Most trailers need more of a wide turn than the truck alone.
As to backing up, again, slow and steady. I like to have a spotter behind me (keep your windows down, and radio off) tell me when I’m about to hit something. Other than that, I always get out of my rig and walk to the back, the visualize how the trailer should back. Then I slowly try to make that happen.
One other bit of advice. Before you load, move, or drive away --EVERY TIME walk around your trailer. FIL was a pilot. Before EVERY flight of ANY plane, the pilot walks around the plane to look for --you name it. I look at windows, tires, hitch, chains, electric, lights, unstowed equipment, unfastened doors and anything else that needs fixing.
It is such a good habit to be in --you don’t want to be on the road and realize you have a dragging chain, a light out, or forgot to close the tack room door.
Oh, and rule of thumb, regardless of what time you need to be someplace, at 15 min for each horse you need to haul. At worst, you arrive 1/2 early some place, at best, you’re right on time because it ALWAYS seems to take longer than one expects to load a horse.
FYI I keep flares and orange cones in my trailer --we use them to practice patterns at shows (the cones, that is).
OH one other thing --if you are at a show and you MUST have access to your tack room in your trailer, use the cones to “mark” a spot outside your door --people will sometimes park so closely you can’t open your trailer door --not good. Put a cone there, and you’ll be able to.
Foxglove