There are two important aspects of good heading technique:

Accurate contact with the ball: Contact with the ball should always be made with the forehead area. From time to time, a player may use the top of their head to flick the football on from a long flighted pass or throw-in. The eyes should always be open (at least until impact) and fixed on the ball and the body positioned in line.

The player's mouth should be CLOSED!

To direct the ball downwards, the forehead must make contact with the top-half of the ball. The side of the forehead can be used to glance headers on and the middle for more direct power headers. In a stationary position, the power comes from the legs, back and neck. The player "rocks" backward and pushes his body forward to meet the ball.

Attacking the ball: As mentioned earlier, this is an extremely important technique. To put power into a header, this requires successful co-ordination of different forces. To gain power, a player can run and jump off one leg to meet the ball. This requires good timing of the run as well as anticipation of where the ball will be placed. After take off, the upper body arches backwards and this momentum produces a snapping action where the body is propelled forward. At the same time the neck is extended then snapped forward in synchronisation with the body to strike the ball with maximum power. The ball must be struck at the top of the jump, if the player jumps to early, he will touch the ball on the way down and lose all power. The ability to run and jump is useful in winning the ball in a crowd of players and should be practised to ensure perfect synchronisation of the action.

It is important to mention the technique for flicking the ball on which is often neglected by soccer coaching books. This technique involves jumping for the ball to play (or continue) it in more or less the same direction where it was played from.

Many teams will play a long flighted pass from the back to the centre-forward who will try to win the aerial challenge and flick the ball on to a team-mate running behind him. This requires good timing and the ability to jump high. The player jumps in the same way as mentioned earlier but drops his head slightly forwards before making a backwards flicking movement with the head to strike the ball (usually with the top of the head) and keep it moving forwards.

To build up heading technique, the coach may want to start with simple practices such as encouraging players to juggle the ball with their head. Gently throwing the ball in the air so the player can head it back to the thrower or to players positioned around the receiver (the receiver can be static to begin with then try attacking the ball) will allow the player to gain in confidence before moving onto more complex techniques. Once the basic technique has been acquired, then differently flighted balls can be played into the player to test and improve his ability (e.g. crosses to be headed into the goal or high balls to be cleared).

Now it's time for a little practice:

Progression 1: Set up in threes, two balls per trio, players in a triangle with about 3-5 yards between them. Working player receives underhand lobs alternately from partners. Lobs from partner A must be headed up to partner's head; lobs from partner B must be headed to partner's feet. Run for a minute and switch working player. Coach corrects the basics as above; emphasises good service. This progression may be too advanced for younger players, who tend to do better by learning one specific skill at a time (e.g., heading downward).

Progression 2: Move players farther apart (about 5-7 yards), and put one ball down. Player A serves underhand lob to B who heads to C. Player C serves A who heads to B, and so on. The difference here is that players are getting a ball coming from one direction and heading it in a different direction as opposed to the simple back-and-forth in the basic work. Emphasise moving entire body to enable powerful headers to be struck with the forehead. This progression, and the progressions which follow, probably will be too difficult for players under about age 10-11.

Progression 3: Groups of four children with two balls, players in a diamond with approx. 5 yards between players. Single working player receives underhand lob serve, locates a player without ball (other than server), and heads to her. Next lob comes immediately. This results in the working player having to deal with balls from a variety of angles, identify a target, and perform the header. As players improve, increase distance and allow non-working players to move around.

Progression 4: 6 players plus coach and assistant (or a couple of parents), each with a ball set up on the outside of an area about 20x20. Working players stand in the centre of the area. On "start", working players make eye contact with outside player and run to them, receive underhand lob for attacking header, defensive header, leaping header, and diving header for more advanced players. The heading player continues round the outside of the server and re-enters the grid to look for another server with ball. Run for a minute and then have players switch roles.

Large Group Work 

Put several players around the edges of a large circle, with about 2-3 players inside circle. All of outside players have balls. Inside player asks for service, then heads ball back to server, and moves to another server. Swap out and inside players after 5-6 headers.

End game

Option 1 (for younger players): Play a 4 v 4 game, but any goals scored by heading the ball count as 2 points. Alternatively, count ANY header as a 1 point. If you taught headers and chest traps consecutively, you might count either a chest trap or header as a goal.

Option 2 (for players 11+): Set up a field 30x40 yards with small cone goals, divide into two teams with different colour bibs and play "toss-head-catch" as follows: Sequence MUST be a "toss" followed by a "head" followed by a "catch". Object is to move down field and score with a header. Ball is 'lost' if a player goes out of sequence or the ball is not caught from the header or the header is not done correctly.

my thanks to soccerperformance for most of the material in this article

games and drills designed to improve heading techniques