I took a Ride Like A Pro (RLAP) class a few weekends ago, & it was an eye-opener.
I don't think it's possible to do lock-to-lock turns, or just full-lock U-turns, without using at least the clutch friction zone. Before taking the class, I tried practicing them in parking lots, but could never get the turns all that tight, & constantly felt like I was going to fall over.
That's because I was doing it completely wrong. You must use the clutch friction zone. It gives you much much finer authority over power going to the rear wheel than any other control.
I had that "ah-HA" moment during RLAP. I would describe the realization as this: you have to apply power to the rear wheel to stay up & keep turning. The clutch is your primary means of doing so. There is a LOT of fine control available between "clutch all the way in" and "clutch fully released." Basically, the clutch becomes your throttle.
Try holding throttle constant (perhaps 2x idle speed) while controlling power application with the clutch. It feels weird to have the engine revving ~2500 rpm but be hardly moving, but you'll get used to it.
More advanced riders will often modulate throttle as well as clutch, but initially it's easier to hold constant throttle & vary clutch.
All this is more easily described than done. The techniques are simple, but not easy. That is, the mechanics aren't really complicated, it's learning to do all of them at once that's hard.
Hope this helps.
2007 Vee with too many farkles