Alright well i start by identifying weaknesses (the middle, flanks, gaps in players)
Then i look at his attack and see the minimum players i need to defend each of his attacking players
Once that is done i look at where i can put my attacking players to expose his weaknesses in defense
Then i try to get a general idea of what orders he will use based on his formation (focus of passing and style) and then i put blue arrows on certain players to defend against that
Finally i put red arrows on the players that will be used in my passing focus and attack (red arrows on DR/L and MR/L for flank attack)
Once you play enough games you get a feel for what works and can come up with counter formations pretty quickly. Otherwise you always have us here at the forum that can back you up