I will add 3 tips more, 'cause timming is the most important thing, but must consider:
-when attacking, you have more chance of sucess if you cross the ball without a tight mark, and just releasing the run button, the player will have more control to cross.
-when defending, take position with the defender, not just wait to the ball and head, go with your defender to where the ball falls and there you must attemp the header.
-It's also important the hability for the player to jump and header, will have more chances to score Crouch or Palermo than Rooney or Tevez.
Same on defense, i always use DF with good habilities on this, cause most of my rivales just runs and cross, so playing with Spain x example, i use Puyol and Ramos as DF, both defends great the header, both are great markers, and Ramos compensates the slow speed of Puyol.