Spin passes are generally used for longer passes in tag rugby because they are faster and more accurate over long distances than the end-over-end pass. A spin pass can also be used for short passes as well for when you want it to be delivered quicker. The spin you create reduces the air resistance so that the ball travels quicker and straighter.

However, the spin pass should not be overused. When your target receives this pass the ball is spinning rapidly and is much more difficult to catch than other passes. It is also worth remembering that wet and windy playing conditions can make the spin pass difficult to execute and to catch. In these conditions passes should be shorter and more care should be taken with accuracy.

Note: This article is for right-handed players making a pass to the left. For left-handed passes, simply flip the instructions.

The ball is horizontal in front of you. Place your right hand, palm facing down on the back of the ball. Your fingers should be on the seam of the ball. This will help with the spin. The arc between your thumb and first finger should point at your desired target.

Place your left hand underneath the ball at the top of the ball. The left hand is a guiding hand, meaning it doesn't have to grip tightly. Simply place it underneath the ball, palm up, so that your thumb is near the left-most point (nose) of the ball.
Pull the ball back to your right hip. While you use your right arm for most of the power on a right-handed throw, you want to get your body as involved as possible for maximum strength. Pull the ball back to your hip, leaving it roughly horizontal as you do.

Try and keep the ball pointing the right way as you bring it down -- you don't want to try rotating it into the right alignment as you throw it.
Turn your upper body to face the target. With the ball still down at your hips, rotate your shoulders to your teammate. The better your shoulders are squared up to them, the more accurate your throw will be.

Toss your arms at the target, keeping the ball low and horizontal. Keep the ball at roughly the same level, roughly hip/belly height, throughout the throwing motion. Your right arm will give most of the power, so focus on pushing from the right on a right-handed throw. Use your left hand to guide the throw to its target.

Your inside arm will stay relatively in place, elbow slightly bent.
Your outside arm should curve a bit outside, with the elbow pointing out.

Follow through with both arms extended at your target. Keep your hands moving until both arms are fully extended. They should point at your target. In general, your left palm will face up from guiding the ball and your right palm will face down from the wrist snap.

Adding extra spin.

Once you’ve mastered the wind up and follow through to make the ball spin you can use your fingers to add extra spin on the ball.

Snap the fingers on your right hand back towards your body. As you finish the throw, slide your right hand down and towards your chest, "pulling" the skin of the ball down and into a spin. This is the hardest part of the motion, but is easy to learn with some practice.

You can also work on snapping your right thumb forward, spinning the ball clockwise as you release.