First a word of advice. It takes some practice to successfully throw a high performance boomerang such as the Orbiter. Don't get discouraged if your first few throws don't come back. Carefully follow directions and keep trying. It takes practice.
Select a large open area (at least 50 yards - 45 metres - in diameter) free of trees and other obstructions. Also, select a day when the wind is very light (5 mph - 8km/h - or less). Higher winds make the flight pattern of an Orbiter boomerang unpredictable.
Although the Orbiter boomerang is primarily designed to be thrown with the right hand, it can be thrown with the left hand as shown in the illustrations in the next point 3 below.
Grip one corner of the boomerang and hold the boomerang high and in front of your right shoulder with the printed side facing you.
Your index finger should be in front of the corner.
Tilt the boomerang 30 degrees down to the right from vertical. Throw the boomerang maintaining that angle while aiming toward the ground approximately 30 yards (30 metres) in front of you. Release the boomerang at about eye level while imparting strong topspin with your index finger.
Your throw may need adjustment to get the boomerang to come back to you. See the adjacent diagram.
The Orbiter boomerang can be "tuned" to adjust its flight. When you purchased it, the boomerang tips were bent 1/8" (3mm) higher than the sides for optimal flights. You can slightly bend all tips up for higher flights and down for lower ones.
Make sure you throw an Orbiter boomerang in a space clear of people and other obstructions. Particularly when learning, the flight path of a boomerang can be quite unpredictable. Cease play if there is insufficient light to clearly see the boomerang in flight.