There are 9 steps as follows:
1.Stretch. Don't just stretch out your arms, though - focus on stretching your whole body before you start throwing. You'll use your legs and your core to throw a football, oddly enough.
2.Know where to grip the football. Hold the football so that your ring and little fingers cross the laces, and your thumb is underneath. Your index finger should be over a seam, and your thumb and index fingers should make an "L" shape.
Don't "palm" the football. Instead, hold it lightly with your fingertips and don't use the inside of your hand on it. Don't grip the ball too tightly. Keep your hold firm but loose and moveable
3.Position your body correctly. Face 90 degrees away from your target. (If you throw with your right hand, turn to the right.) Turn your pivot foot (opposite your throwing arm) so that it's pointing toward your target, and keep your eyes on the target.
4.Keep the ball near your ear. Before you throw the ball, keep it up near your ear as you get into position. That way, you can throw the ball quickly at any time, without winding up and giving away your throw.
5.Wind back. Wind your throwing arm back a bit behind your ear.
6.Throw in a half-circle. Practice this motion a few times before you let go of the ball. After you wind back, move your throwing arm forward in a circular arc. Release the ball mid-way through the circle. Your empty hand should then head toward your non-dominant hip, palm facing away from you.
7.Use the rest of your body as momentum. Though the direction of the throw comes from your arm, a lot of the force comes from the rest of your body. Step forward with your non-dominant (or pivot) foot, and move your non-dominant elbow down toward your back. Again, practice this motion a few times before throwing.
8.Release the ball with your fingertips. As the football leaves your hand, it should only touch your fingertips. The last part of your body the football should touch is your index finger - this will provide the spin that makes it a spiral throw.
A proper throw will feel like it's only utilizing the thumb, index, and middle finger. Good release will "roll" off of your index and middle finger. To impart more spin, you may snap your wrist through as you follow through to the hip. The other two fingers on your hand stabilize the ball as it's being flung. They should not be used to impart spin on the ball, unless you really know what you're doing. The most important finger to throwing a spiral is the index finger, as it is the finger that holds the most leverage in putting spin on the ball.
9.Keep practicing. Small adjustments in how you position your body or hold the football can result in a better throw. Keep trying until you start getting the force and distance you want.