Prepare the area you'll be painting. Because you're using an air-powered sprayer, it is inevitable that some paint will spray into unwanted areas. Put drop cloths on the floor and use tape and newspapers or plastic to cover the areas you wish to protect.
Attach the spray gun to the compressor hose and start your air compressor. Allow time for the air pressure to build.
Test the HVLP spray gun on a piece of old wood or paper. This will allow you to gauge the pressure as well as the pattern. If necessary, make the proper adjustments to the spray gun. Of course, read the owner's manual for your specific spray gun for proper adjustment procedures. You can turn the knob clockwise on most sprayers to narrow the spray pattern, and counterclockwise to widen the spray.
Grip the spray gun securely and hold it approximately 12 inches from the surface you wish to paint.
Press the trigger and spray the paint directly onto the surface, using a smooth, side-to-side motion. When spraying, you should cover approximately 3 inches per second.
Release the trigger only after you've passed into the area of newspaper or plastic you put in place earlier. Start another pass just beneath the previous strip, going in the opposite direction of the previous pass. Each pass you make with the sprayer should slightly overlap in order to blend. Do not swing your arm to make the passes; you must keep the spray gun straight at all times.
Continue spraying in overlapping passes until you've finished. Keep the spray gun level and at the same distance from the surface throughout the entire job. Also, do not allow the spray gun to sit unused for more than 15 minutes, because paint will begin to harden in the nozzle.