I came here to post something similar but after searching first I found this thread. I am only really a beginner, I have been playing about a year now, but only about 6 months of that have I been properly "training" rather than just hacking.
Lately I have been keeping a training notebook. I take it to the range and note down each shot, writing a dot for a shot I would be happy with on the course, and an x for a bad shot.Anything that would hit the theoretical green I am imagining (my range doesn't have exactly defined target greens, just distances) or just off is considered OK, and anything which slices/hooks or isn't hit clean is an x. I also note down what went wrong with the shots that go awry, and at the end I will write down lessons I have learned, what went right or wrong, and work out the percentage of good shots. Lately it has varied from 80-90%, and usually the difference between an 80 and a 90 is just one or two balls. I find it helpful because knowing I am headed for a high percentage adds pressure, so I'm not just standing there whacking balls. It also means I will practice each swing and think about whether I am too steep/shallow or whatever might be going wrong. I am finding it a good way to take the range a bit more seriously than most people I see there.
Usually I will start with the PW, then move gradually (one or two balls for each club) through to the driver until I consider myself warmed up, ironing out anything which is going wrong along the way. Once I get to the driver I imagine that I am on the course, and will hit driver, then an iron, varying the length of the iron relative to how long I am imagining the hole is. I will do this until I have a few balls left and then finish off with the PW again, thinking about what I have learned today. I have found a journal is very good for recording how well all this works out.