The actual throwing action

Getting down to some actual throwing. It may be tempting to throw as hard as you can at first but if you end up throwing a lot of knives in one day you'll just end up tiring yourself out. The whole action is a relaxed and easy affair and should require surprisingly little effort if done correctly. You can always add some power later when you have the action all sorted out.

Throwing action 1
The wind up: The arm holding the knife is drawn up to behind the ear or a bit further.
Throwing action 2
The action is confortable and easy. No stress on the elbow or wrist. It is more the action of your arm that imparts creates the rotation of the blade, rather than a snap of the wrist. Of course, there's no rule to say that you can't use a wrist snap but perhaps try this later once you have learned to throw reliably first.
Experimentation is all part of the fun. Have some success and then branch out.
Throwing action 3
Note how there is no snap of the wrist. The knife is allowed to slip from your grip at the precise moment. Learning to throw the knife consistently will be the key.
Throwing action 4

Follow through: The arm is not snapped back but rather allowed to follow its natural line. Some throwers prefer to leave their throwing hand pointing at the target and allow their left hand swing out and down as part of the action. Note the feet are still in the same position, ready for the next blade to be drawn. In competitions, against the clock, the less you move around the more quickly you'll be ready for the next shot.

When the throw works and the blade sticks squarely you will know that you have your distance and action correct. Memorise what you did and replay it over in your mind, even when you are not out throwing. This is as good as actual practice.

Reverse throwing technique

Reverse Throw

As you progress you might want to experiment and the reverse throw offers a novel change. Gravity will work against you and it's a fun technique to perfect.

Keep experimenting!