There is no rule such that the bathroom lighting should be provided only in the ceiling or is better if it is provided at the sides or on top of the mirror. One has to fix the bathroom lightings according to one's taste and the mood that he or she wants to bring into the room. Even for a small bathroom, people, these days, go for two or more lighting fixtures. Thus, lighting is the most important factor to be considered in any modern bathrooms.
Lighting for the bath come in two options: either those who are already incorporated in the furnishings, or those you buy separately. Choose a filament lamp bulb for a small cost, in a bright colour, similar to natural light. Choose a spotlight if you want something to consume less energy, but a bigger price than a bulb. And if you choose the neon light take into consideration the colder light and the higher price.
It is wise to use flush-mounted ceiling fixtures, owing to the fact that these come with bulbs that are enclosed by a kind of cover. The cover is essential as it acts somewhat like a lamp shade and helps in diffusing the light as well as protecting hot bulbs from breaking and cracking from contact with water vapor. The best would be to have the right balance of ambient bathroom lighting and task bathroom lighting. This will give your bathroom proper illumination and make your bathroom experience worthwhile.
Bath lighting must meet three conditions: to be functional, aesthetic and to have a special ambiance. For the daily tasks (shaving, make up, etc.) you needed a strong light and for moments of relaxation, such as a bath in the tub, you need a discreet light. Also the bulbs that you use must provide the amount of light needed to properly light this room.