Place a slide horizontally into the stage clip of the platform. If there is printing on the slide it should be placed so that you can read it. At low power, you can safely focus the specimen using the coarse adjustment. Focus the specimen with your right eye. The left eye is focused by turning the base of the left eyepiece.
Eyepieces move apart or closer together for convenience.
Center the specimen. Use the condenser focusing knob to sharpen the outline and then go slightly out of focus until you get a faint blue halo. A red halo is not desired. Open the iris diaphragm only enough so that the light completely fills the viewing area as you look into the scope. Opening this more reduces the quality of your image.