You can influence the actual form of the turn through the pressure you put on the skis. During the turn, you can put more pressure on the skis, thereby bending them even more, so that in the end they turn more and more sharply.
Reducing the pressure of your skis.
Likewise, you can reduce the pressure on the skis while you are turning, thus making the arc flatter and longer. You increase the pressure by pushing your weight down towards the skis. On the other hand, you can "pull" your legs up towards your body to reduce the pressure on the skis. You can actually make the skis turn more or less by increasing or reducing the pressure from your up and down movements.
Increased pressure at the end of the turn.
Try the following exercise: Stand on a bathroom scale. Crouch down by quickly lowering your body. You will notice that the numbers on the display fall rapidly. Conversely, when you "land" again and begin to straighten out, the numbers rise rapidly over your normal wight. This exercise illustrates that you yourself can influence the amount of pressure that you put on the skis.
The correct up and down movements help to form the turn. By not influencing the skis too much during the start of a turn, the transition from the old to the new turn becomes easier. You should, therefore, save your strength and energy at the beginning of the turn, so that is is much easier to steer the skis in a new direction. When you have started the turn, and the skis have begun to dig into the snow, you can increase the pressure on them with the help of your weight to increase the edge grib. Therefore use only a little strength to pressurize and edge the skis so you can steer them through the last part of the turn.
The transition phase between turns is, from experience, a critical point in skiing. You should try to get through this phase as quickly as possible. A ski with pressure on it is far more stable than a ski without it.