For those of you who are having issues with first time shots and headers still, i have finally mastered it after 2 hours training. To perform a first time shot, header or volley etc... press the shoot bar to your preferred level of power then when you are about to make contact press shoot again much like you do with a knuckle shot, works every time... It isn't a lag issue like everyone has thought and complained about, I hope this helps everyone out a load
I'm sooo happy, the only problem i had with the game, apart from keepers and i've cracked it.
EDIT: Ok so its a bit more complex, so here is basically what you have to do for different situations....
Throughball to shot: throughballs seem to have no issue as the player is running onto the ball in his stride so you can pretty much do whatever shot you want, so for some cut backs, try pressing throughball instead of pass.
Short pass along the ground to shot: Quickly double tap shoot after you have performed the pass.
Longer pass along the ground to shot: Like stated in post above, press once for power and then once just as you go to strike the ball like a knuckle shot.
Cross to Volley: press shoot once for power and then once again as the ball drops to you.
Cross to Header: This is again a quick double tap after you have crossed the ball, simply because you have to give the player the time to jump then head...
Hope this really helps you guys....
Oh and remember, if you want a cross to go on someones head, you have to full power it, otherwise it comes in too low and you will end up volleying it.