referring to internal and external side mirrors.

In right hand traffic in the car is installed the rear view mirror inside the cabin and exterior left side mirror. The right side is necessary if the rearview mirror is not able to provide own review, for example when back glass is curtained shutters. If vision through the rear window, no in the design of the car, the rearview mirror can not be set.

to correctly set your side mirrors, turn your head left, look through the window and turn the left lateral mirror (and stay in the time) until not disappear the image of Your car.

then rotate head to the center of vehicle and set right side mirror while the car is not will no longer be reflected in it.

Lateral mirrors should stand so that three mirrors together give You a complete overview of the environment. Blind spots should not be.

Custom rear-view mirror necessary for the review of the road to the back and sides of Your machine. adjusting the rear view mirror is very important. The center of correctly adjusted mirror approximately should coincide with the visibility center in back glass. In a lateral mirror the driver should see the side of your own car, to understand position of other participants of movement relative to my car. Such reflection, however, must take in the mirror not more than 2 cm, otherwise the angle will be very limited. The horizon line should be slightly below the middle of the mirror.

How to check the overall settings of the mirrors? have someone slowly walk around the car around at a distance of about two meters and accompany this bypass with a look in the mirror. If reflection of Your assistant disappears in the rearview mirror and immediately appear in the cabin (and Vice versa), the settings are made correctly. Similarly define, whether there are dead zones where the assistant cannot see. The viewing angle can be increased a little closer to the steering wheel.

Source: http://www.avtoobzor.info/articles/vozhdenie_automobilya/zerkala.html