Do not turn off the systems, adapt your driving so you do not activate them.
I disagree with this, strongly. Disable the traction/stability control as you, the individual, are comfortable with. Realize that turning it oyf increases the likelihood of an off or spin on the track. But also realize that driving with the stability/traction control on means you don't have the opportunity to develop the car control skills that might help. Additionally, depending on the stability control system, you may be significantly slower around the track if you leave it on.
In one of my track sessions, with the stability control system on, I braked too late for a corner and turned in too late. My movements were also harsh. This put the car into a four wheel drift. The stability control lights flashed and flashed. But I'm not sure how much the system was actually doing - it didn't cut power (which the system in my car tends to do if the rear tires spin). It may have done some selective braking, but it still took the right steering and throttle inputs from me to keep the car on track and resumed pointing the correct direction. I'm not saying I could have saved it without the stability control, but I am saying the stability control alone couldn't have saved it.
Additionally, the stability control on my car only has one level. It's either on or off. The one setting it has is extremely paranoid, allowing no slip. The traction control will cut in before the limited slip diff on the car has a chance to transfer torque. Trying to track this car with the stability control on is torture. Smoothness doesn't help - some slip is expected to be used when tracking, and this system allows
none (if it can help it). Thus, if the system in your car is like mine, I'd suggest turning the system off, and using low speed maneuvers to work on your car control skill. Just understand the risk you are accepting when doing this.
In cars with a more relaxed stability control, or with multiple settings, it would be wise to run with the stability control on sometimes, and off other times, so that you learn both smoothness (enforced by the stability control) and car control skills.
Again, I state, though, that turning off the stability control does increase the risk of damage to your car and yourself. Only do so if you are aware of the risk and ready to fully accept the risk yourself. In other words, if you turn off stability control and crash, it's not my fault.