Remove everything from the room. Cover all areas that won't receive texture with plastic sheeting held in place with masking tape. Cover all outlets, switches, light fixtures, windows, frames and baseboards with plastic.
Lay plastic sheeting on the floor, making sure all areas are under plastic. Tape heavy-duty plastic over all doorways in the room to prevent texture floating elsewhere.
Wear safety goggles and a cap when working with texture for protection. Put on a long-sleeved shirt, buttoned at the wrist, to keep the texture off your arms.
Pour a half-gallon of water into a 5-gallon bucket. Add some of the texture. Attach a mixing paddle to a drill and start to mix. Add more texture until the consistency is about the same as pancake batter.
Use a little more water if the mixture seems too thick -- if the mix is too heavy it won't push through the texture blower properly; if too thin, it will drip down the Sheetrock).
Attach the texture blower to the air compressor. Place the texture in the hopper of the texture blower, being careful not to overfill it. Start the air compressor.
Hold the texture blower so the nozzle is about 12 inches from the Sheetrock. Move the blower from across the surface of the sheetrock before you start spraying to begin creating an even texture. Keep an steady spray; it can be heavy or light, depending on how much texture you want to apply to the Sheetrock.
Move the texture blower in different directions across the Sheetrock to create a consistent pattern of spraying on the surface. Stop after applying the texture to an area to check your work before continuing; this will allow you to see if you have achieved a good coating on the Sheetrock.
Continue spraying until you have covered all the Sheetrock and check to ensure the texture is well distributed over the surface. Keep the nozzle of the blower the same distance from the Sheetrock the entire time you're spraying