First off all let me warn you. If you are here for a download tactic that you can plug and play, this is not the thread for you.
I will explain to you my method to achieve great things. With this method in my first season at Borrusia M'Gladbach. (media expectation = 11th) I became third in the Bundesliga and survived the group stages of the Champions League. I also became runner up for the German cup. You can say I exceeded all expectations with no additional signings at all.
Look at your team, their strengths weaknesses and formations.
Then decide your style of play. ( Passing style defense line etc.)
Create 3 different formations using this style of play. An attack minded formation, balanced one and defensive one.
I used 4-2-3-1, 4-5-1 and 4-4-2
Now you have 3 tactics using the same style of play but different formations.
What I did is cycle them, and use an attacking formation against weaker teams and defensive one against stronger teams.
I advice you to make subtle changes to your style of play when necessary. But I almost didn't during the entire season. Also during a match you can change your formation at the hand of the game. If I see Bayern Munchen going on an all out attack when I'm 1-2 up and I was playing 4-5-1, i will change to my 4-4-2.
I use control as my strategy in my style of play but this depends on you and your team. I also change this according to the match and opponent.
As I said this is not a tactic this is a method/guide to make your very own effective tactics, wich I find gives me much more amusement then using a plug and play downloadable tactic.
I hope this was usefull!
Ciao e buon divertimento, FORZA ROMA!