There are three points to consider in the pole touch. The first is where to touch.
Stand in a dynamic position prepared to traverse. For long radius turns, hold your arms stretched out ahead of you. In medium radius turns, bend your elbows and bring your arms in a bit. In short radius turns, bring your arms into a somewhat more tighter position. No matter what size of turns, keep flexible to quickly adjust when there is sudden change in terrain.
The second thing to consider is how to pole touch.
The Pole touch is just a gentle touch. You don’t need to "plant" the pole. Hold your arms somewhat steady and let your wrists swing the poles. The pole only touches the snow for a brief moment, your wrists are already in motion. Continue that motion and roll that hand forward and over the pole, and the continuous motion will avoid getting it bounced back towards you. The two poles swing continuously, alternating. As one swings forward, the other swings back.
The last consideration is when to pole touch.
The timing is different for the type of turn your’re going to be making. In long radius turns, the pole touch is when your skis are pointing across the hill, right after your skis have crossed the fall line. The touch triggers the new turn. During the medium radius turns, the pole touches right when your skis point across the hill. The touch coincides with the start of the new turn. In short radius turns, the touch happens just before the new turn starts.
There are situations where a more aggressive pole touch is required. On steep terrain, an aggressive pole touch helps in pivoting of the skis quickly and helps control speed.