As for every corner of the house, even for the bathroom, it is imperative to create the right lighting. The bathroom must not be either overly illuminated or overly dark, in which case it may be difficult to perform the functions due. Ideal is to use different levels of light, which can be handled individually, in order to be able to choose the most suitable lighting and lighting requirements at the moment.
The general lighting of a bathroom should be uniformly widespread. This is usually done with ceiling, recessed or suspended lights. Obviously, depending on the size of the bath you have to understand how many light points are needed. In doing so, one must consider the functional (and necessary) lighting of the different areas of the bath: the tub or shower, the washbasin with the mirror.
If you have a bathtub, consider managing lighting with a regulator so you can keep it low when you want to relax, maybe using some candles.
The sink area has to be very well illuminated. Better if the light is directed on the mirror. In this area a single light source would only create annoying shadows.