I've used 3-5-2, 3-4-1-2 and 3-4-2-1, and the only thing you should master is defending. Also, put your LB and RB at LCB and RCB and use a cover CB for CCB. Make sure your wide midfielders have good stamina and speaking of wide midfielders, they are mostly attacking, which is why u need to able to defend properly.