The pile driver is ideal for folks who like to manually stimulate themselves externally while being penetrated. It’s also a great pose for intense G-spot and prostate stimulation (squirters who enjoy watching themselves ejaculate would enjoy this). The receiver lies on their back and lifts their legs backwards until their hips and lower back raise up, similar to the plow pose (Halasana) in yoga. Being the receiver you’d require more flexibility and range of motion, holding onto your ankles can help keep you stabile. Having a headboard would make things easier for the receiver as you can latch your toes or feet for extra stability. Basically find a way to position your feet so you won’t accidentally kick your legs down and give your partner a whack in the face. It’ll also allow you to use your free hand to touch your partner’s chest or rub your clit.