Is land nav training alone effective?

[AspiringWarrior]

Hey guys, I'm pretty green at map/compass/terrain association land nav. I'm extremely proficient with GPS but have minimal experience with low-tech methods. I need to hammer on this weakness.

From my very limited previous training, the basic land nav training format seemed to go something like this: get first grid, plot grid, verify with an instructor, plot azimuth and distance, proceed to grid, get next grid, rinse, repeat. There seemed to be pretty extensive prior set-up work on the course by the instructors before the students showed up.

This brings me to a critical question: is training significantly more effective if *someone else* sets up the course before I run it, or could I set up my own courses and still train just as effectively? How important is it that I have no prior idea where the points are?

I want to be a land nav monster by the time I show up to selection. Is training on my own every weekend the right path towards that outcome (supplemented by out-of-pocket-funded civilian classes when available), or is there a better way?