My life got a lot easier once I learned to figure out which cones are outliers. Most courses fall into a flow, something like “if you can’t see it (more or less) in front of you it’s probably off your left shoulder, except for 4, 12 and 16 which are off the right.”
I keep that kind of plan in the back of my head in case things go sideways. Sometimes it helps My favorite time was when I was all the way on the far side of the field, then had to gallop across the bottom to other side to finish the final 1/3 of the course. I was about 3/4 of the way there when I realized I forgot a 13, whipped around, galloped back and did that cone (it was somewhere in the middle), then galloped through the rest of the course never hitting the brakes. And with no time faults. He is a very fast pony!