Place the piece of furniture on a drop cloth to prevent stain from getting on the floor. Open up any windows in the room to allow for proper air ventilation. This is not only important for your safety, but will speed up the drying process.
Mix the stain as directed by the manufacturer. Products vary, so it is important to read the label on the can thoroughly before you start using the stain.
Fill the reservoir tank on your paint sprayer with the mixed stain. Aim the paint gun at a piece of cardboard or scrap wood and spray the stain. This will give you an idea of the gun's force and coverage.
Spray the piece of furniture with the stain. Use long, even strokes and always spray with the grain of the wood. Allow the furniture to sit for about five minutes after you cover it with stain.
Wipe away the excess stain with clean cotton rags. Keep wiping the furniture with the grain until no more stain comes off on the rag. Apply additional coats of stain if desired, allowing the furniture to dry between coats.