I usually find where my players play the best and keep them there. I've had left-footed MCs play on the right and vice-versa. The ones you can't do anything with are the left -sided players (DL/DML/ML/AML) that are right-footed and right-side players that prefer their left foot...

I suppose my classic example is the Palace Casuals right-winger (screen shot taken when I finally decided to put him out for sale...

Player's weight, height and preferred foot.-pc-johan-shaqiri-stats-final-hl.jpg

...not many goals, but over 90 assists...