This kind of spinning also relies on very strong inner thigh muscles to keep one's legs, from shoe to torso, stuck together under one's center of balance. This is much harder than it seems, especially if the lead is not so strong or the floor is not so smooth. When doing spins, keep your feet as close together as possible. You want weight on the ball of only one foot, and you can change from one foot to the other during the spin, but the non-weighted foot should be right beside the other and should be just skimming the floor. Again the point is to keep your c.g. as close as possible to the axis of rotation.
Many turns require the follower to turn in place.
Try not to drift away from your partner when turning. That is, maintain your balance during the turn and stay atop of your feet. This is essential to staying in a slot during West Coast Swing. After all, he's the one watching her spin and can see where she's headed when, if she's off kilter, she's watching the room blur by. Don't feel hesitant to turn to unravel out of an awkward position.