Many of the movements performed in CrossFit are quite linear. This is not a bad thing as they are based off of some very useful and essential basics (think squatting, pushing, pulling, deadlifting etc.).
These are all fine movements, but occasionally it behooves one to get out of the habit of only performing movements and motor-patterns that allow for an ideal set-up or condition. Barbells, kettlebells and dumbells are nicely balanced and relatively comfortable to use. They are designed and optimized for this purpose.
Finding some 'austere work' to do can fill in some gaps that may be present in your more conventional conditioning. It also serves to keep things fresh in terms programming and just plain ol' fun factor. Basic movements become anything but with odd-objects and 'additions'. Check out how many 'additions' Coach A.O.D. has on his person:
Of course all your regular lifting mechanics apply as much as can be expected (spine extended, abdominals braced etc.)...ask your coach for some movements to play around with!
-Adrian "that-really-sucked-so-right" Bozman