Hold the can inches from the desired canvas, with the spray nozzle facing directly toward the surface you wish to paint. The angle of the nozzle to the surface will determine the shape, density and consistency of the sprayed paint. This "trick" enables the artist to create a highly concentrated spot of spray paint, where the drips are part of the effect of having the spray can close to the painted surface.
Hold down the nozzle while the can is in this position. As it begins to spray a thick dot on the surface, discontinue spraying. Be careful not to spray for so long that the paint will run completely down the surface. Instead, it is ideal that the drips are minimal, so they appear as part of the spot. The resulting effect should be a drippy spot on the surface.
Hold the can a foot from the desired surface. Push a series of short bursts of the spray can in different areas of the surface. This should create a sprayed texture of whatever color paint being used, where it appears as if a spray can was used to add a minimal burst of color.
Holding a piece of cardboard in front of the spray nozzle creates different splatter effects, which can be used to create more shading or texture on the painting surface. The cardboard ensures the spray doesn't go everywhere and is directed to a specific area on the painted surface.