Remember that the footwork in Pinan 2 is the same as Pinan 1. Each strike sequence, however, will be different so make sure to throw the correct strike to the correct target area. For this drill it is a thrust punch to the groin (bend those knees).
Be sure to have good chambers on every kick. This will help maintain good balance so you can set into the correct half moon stance each time. You should not be falling into any stance because of a lack of balance.
Work this slowly until your body is comfortable with the rotation. The most common mistake is that people try to bring their left leg around with the strike instead of leaving it in place. The non-mirrored view starts at 01:35.
The timing of the hands and feet in the beginning is very important. Also, make sure to have a nice low stance for all of the strikes at the end of the technique.
Self Control is critical when working with a partner. The goal is to be able to do this, as they demonstrate, at a fast pace and striking right next to the target without making contact.
When you are working with a partner, make sure your footwork is on point. Since you are going at a slower speed, you should easily be able to adjust your position before executing your combination.