Summarize this article in one sentence.
A gentle, side-to-side shake is all that is needed. Once you have shaken the bottle, remove the green cap on top of the bottle. Priming the spray in the bottle helps ensure that the medicine flows freely. To prime the spray, push down on the pump several times until a light spray comes out of the bottle. If no spray comes out after priming, the nozzle may be clogged. Remove the nozzle by lifting it up from the bottle. Fill it with water from the tap and pour the water out. Let it dry on a paper towel before snapping it back onto the bottle. Try priming the bottle again.  If it still won’t release medicine, soak the nozzle in a cup of warm water for several minutes. Let it dry before putting it back onto the bottle. Clean the nozzle at least once a week to ensure that it works properly. Always prime the bottle again after rinsing the nozzle.

Summary:
Shake the bottle before removing the cap. Prime the spray when you first open it or after 7 days of no use. Clean the nozzle if it is clogged.