First thing I do is to look at where the FK is from. If you get a lot of freekicks against you on the flanks, that you are able to cope with, you dont have to do too much. If these are getting you into trouble, take a look at what kind of trouble it is. Is it the man-marking that is bad? Do your players loose battles in the air?
If those are the case, try changing the setup of who is marking players etc.
If it still causes you problem after you have changed your instructions there, I recommend to try and avoid the freekicks. Take the players that are causing the dangerous freekicks down from hard to mixed tackle, or from mixed to easy.
If you are getting a lot of shots against you from freekicks outside the area, which is causing your keeper trouble, you have to adjust the numbers of men in the wall. The more men in the wall, the worse it is for the keeper to see where the shot is going, and he will mostly just stand still, watching the ball fly past him.
If that doesnt help, change tackling instructions again for those who are causing the dangerous freekicks.
Hope that is helpful
(only 3 more to go now...)