I use wiimote and numbchuck exclusively. I tried the classic controller pro and a couple other methods like gamecube controller and zapper, but this is what works best for me:
Rest your right hand with the wiimote on your leg when you are playing to reduce excess movement of the reticule. Make small movements with the reticule and adjust the sensitivity settings for the device accordingly. After a little trial and error, you will find what works best for you. This helps prevent unnecessary "flailing" in close quarters, enables very accurate turning, and steadies your shot on long range.
I think this is one of the best reasons to buy this game - it allows for a LOT of control customization of any 1st person shooter I have seen.