Thanks James,
My technique varies depending on the course design, lighting and speed of the dogs. In general:
I pick one obstacle and set the focus preset button for that obstacle. Occasionally, I'll have two obstacles at the same distance one left and one right, but that is rare.
I pick another / other obstacle(s) that I can have a bit of lead time on. For those, I focus on the obstacle and use the AF-L button to lock it down. Then I go back and pan with the dog on approach and through the obstacle.
For the rest of the course, I follow and track in Continuous Servo mode.