More on opening and forming the skin:
The dough ball goes into the flour top down. Flip it and take it out of the flour. The top is now up on the work surface. Look at the underside of your hand - your fingers have three segments. With your fingers extended as far out and up as possible - so that your fingers have an upward bend, press your fingers into the dough so that the middle segment of your middle finger is the first contact point. With a tiny bit of rocking motion, roll your hand back towards you just a little pressing the dough slightly towards you. Your fingertips should never touch the dough. Using as light a pressure as possible, start inside of the cornice by about ½” – ¾” and work from top to bottom as described above protecting and forming the cornice at the top and the bottom. The pressure is not much more than the weight of your hands. Flip the dough and turn 90 degrees as you set it down. What was the left and right sides are now the top and bottom. Repeat the process. You should now have a cornice all the way around. Protect the cornice. Flip the dough again so that the top is back facing up. Use your fingers the same way to spread the dough a little more. It's OK to gently tug on the edges to stretch and round out the skin. If needed, place the skin over your knuckles and turn it 360 degrees pulling slightly apart with your hands as you go around but mostly let gravity work. If you do this, be careful as you can quickly thin out the enter with a supple dough. When you finish be sure you end up with the top of the dough facing up.
Remember that sliding the dough onto the peel and/or stretching the edge on the peel will also increase the diameter, so you don't need to open the skin to the full final diameter. Stretching to the final diameter on the peel has two additional benefits, 1) it does not thin out the center of the dough, and 2) you get to fix the shape so it goes in to the oven round - or oval as needed - the steep launch angle of a short peel into a home oven tends to deliver a round pie onto the stone round. The shallow angle of a long handle launching pie deep into a WFO will elongate the pie along the axis of the direction the peel is pulled out from under it. In this case, a slightly oval pie with the long axis perpendicular to the handle of the peel will result in a round pie on the floor.