The secret don't exist, theres no secret. To be successful is a mixed of: Successful= (formation+orders+decisions by default=(correct man in corners and fouls) )x(nº of key players) / (appropiate decisions during the match(=good substitutions basically) then thats = success.

Now the question is:

have you played friendlies to see the man that have to shoot the fouls and one for the corners? (one per everything is enough)
Have you a min. of 1 key player as a ST or MC that can do the 1/2 of the work that you need to win a league?
Have you seen what contribution do your players iduring the matches without take in account the raings?

now sure that by my side can give you a better opinion if you put a pic of the team, the section of goals scored by all players + matches played + raings.... try to upload this page and sure all will be more clear. Because what you need is a key player probably...