Key Points to a good Throw In
1) Two hands on the ball. Make a "W" thumbs together, fingers spread wide.
2) Face the direction you want to throw, keeping your hips and shoulders in the direction of the throw. (No twisting)
3) Both feet must stay on the ground. (No jumping)
4) Ball must come all the way behind the head.
5) Throw forward and release the ball above the eyes.
Practice this at home to get good at your throw ins and to get more distance.
Don't forget the 5 KEY POINTS above !
Just as important as the throw itself is where to throw the ball and where you need to be to receive the ball in order to take advantage, maintain possession , out maneuver your opponent and game ground on the field.