Everyone showers, but not everyone showers the right way. Although these habits are common, they're not very healthy.
It may be easier and more convenient to just wash your face while you're in the shower, but that may be doing more harm than good. The water you use in the shower is most likely a lot hotter than the water you'd use to wash your face in the sink, and washing your face with steaming hot water is not recommended by dermatologists. Wash your face only with warm water to avoid dilating your blood vessels (which just sounds scary) and drying out your skin.