I always set out at the start of the season to have my top eleven players in the traditional 4-4-2 formation. I focus on getting 11 really good players to fill those positions, with many of the players able to play at least two positions to give more fluid options.

I also always have a AMC in the squad so I can change the 4-4-2 to a 4-4-1-1 if needed.

I don't worry about what formation my opponent uses. I focus on my team and my team alone. A lot is made of changing from the traditional 4-4-2, but it offers fantastic balance and allows the user to change to a more offensive or defensive formation pretty quickly if the need arises. One sub changes a 4-4-2 to a 4-4-1-1, a 4-3-3, a 5-3-2, a 5-4-1, a 3-5-2, or with a AMC in you could go to a diamond etc...

The problem when you start going for more "advanced" formations is then you often have to get specialist position players in, or you are holding out that key positions don't see injuries or suspensions. Play too attacking and you get punished on the break. Play too defensive and you get no service to the front players. Changing your formation based on the opposition is daft because you are basically conceding to the opposition before a ball is kicked that your team is inferior.

If you have faith in the players in your team then you should stick to your formations and force the opposition to make the rash changes if they are needed.