Ive been working on leg awareness with Rey lately as I do with all of my dogs. This video focuses on her rear placement with a movable target. Typically I prefer to use a stationary object however when puppies are in the initial phase of learning about target placement, I have found that having a moveable object early on teaches them to just "figure it out"over time.
After they have the basics down I would switch to a more stationary platform. So far she has caught on very quickly and I couldn't be happier.