What exactly is the right way to do anal contractions? Are you suppose to just squeeze the butt together? What exactly do you do?
Imagine you've got the runs and need to hold it in until you reach a toilet. You hold it in by an anal contraction.
Likewise, you can also contract the PC muscle in such a was as to stop the flow of urine - that's another part of the muscle.
Most people contract the whole PC muscle at once but with practice, you'll find there are three separate areas that can be contracted separately: anal, 'urinal' and an area in between.