Pivot slips by the bookI'm sorry but there are a lot of progressions that will help to build a solid pivot.
I'm studying for my level IIII and the study guide has a clear path to a successful outcome. I will use some of theirs and some of mine.
1.) Side slippping in a corridor is an excercise that promotes , hip countered movements. Praticed 1st on moderately steep and smooth terrain. Intermediate student corridor is alittle wider (12 feet+), more advanced/ expert should be alittle more the one ski length wide. The goal is to slip vertically within the boundaries without skidding foward or backwards. This is a difficult excercise to perform when first tried. The student must continually balance themselves over the entire length of the skis to keep them sliding vertically and stay within the corridor.
2.) Picking a distant object directly down the fall line as a target ands using the hip countering movements is essential to a well executed slip in the corridor.
3.) Try both sides for we have a strong and a weak side, because of our body semmetry is not exactly the same and we compensate sometimes very finely and othertimes more grossly.
4.) The guide books says "You must twist the torso firmly toward the fall line,streatching the latissimus dorsi muscle and a good range of motion of the hips (made more available by slight flexion by knee and ankle joints)"
5.) The guide book goes on buy saying " To Maintain a strong upper body with the hips positioned fairly high over the feet and keeping the spine fairly erect as to not create a weak stance by putting too much weight in the back seat, remember to keep the hips toward the fall line and have the uphill hip, knee and foot about a half a boot length ahead of the downhill compliments.Very important is to maintain contact between the shin and the tongue of the boots while feeling the bottoms of the ball , arch and heel ( whole foot) of both feet, creating that centered stance.
6.) Hockey and linked Hockey stops are part of the progressions used to
get to Pivot slips. They help with Edging and Pressure and also by learng to actively turn the inside leg and foot to keep from displacing into a christie also promoting an open countered stance of the hips. Linked hockey stops adds a change in direction by extending the legs and pointing or twisting knees and ankles towards the new direction The manual says to " Use th legs and the feet to turn both skis into the fall line. Pivot the skis until they point straight down the the fall line. Guide in the fall line for a moment , then use the legs and the feet to actively turn or pivot out of the fall line to complete the turn."
7. Pivot Slips, next we add a some rotary, steering or guiding by turning both legs and feet at the same time, a balanced stance is essential to stay within the desired corridor. The movement used is a flexing directly over the skis, allow them to slip and move down the fall line and weight should be about equal between both feet.
The pivot slip in my book uses all the center line movements as outlined by PSIA. Balance, Rotary, Edgeing and Pressure. I have even seen guys/gals do it at 40 mph on one ski and not just once.
So go play with it.