Vanity lighting gets top consideration because these fixtures work the hardest to illuminate the head and face for grooming. The most common mistake people make is putting recessed ceiling fixtures directly over the mirror. These cast shadows on the face, making daily grooming rituals more difficult.
Vertical fixtures or sconces mounted on either side of the mirror are best for casting an even light across the face.
But given the size and positioning of some vanity mirrors, sidelights can be impractical (mounting them directly to the mirror is always an option, but at greater planning and cost). Only then do I suggest a fixture for over the mirror. It should be placed 75 to 80 inches above the floor and, like all vanity lighting, contain at least 150 watts — ideally spread over a fixture that's at least 24 inches long so that the light will wash evenly over the hair and face.
The shower is a secondary area of task lighting. In smaller bathrooms, if the stall has a clear glass door, a dedicated fixture may not be necessary. Otherwise, I recommend a recessed light with a glass lens (plastic will yellow). Similar recessed fixtures work well over a freestanding tub or the toilet.