Pretty rough in that I use it for more then just taking pictures!! heheheh....still lucky I guess as all are still fine. Have not lost a single picture from them. A year now for all 4 of my CFs which I use in my D70, CLIE PDA and my cardreader since I do use them as backup module when I bring work from office to home and back. Totally no sense of maintance in my case heheh.
i think what you are asking is how to keep it in good working condition. to protect it, i use a gepe card safe. i remembered reading it as water resistant, moisture resistant, anti-static resistant, etc. false protection? i do not know.
I have a CF card for my PDA for a few years and I really abuse it by throwing it in my drawer, put in pockets etc without any form of protection and it is still working in perfect condition. However I didnt dunk it in water. I have other cards and the worst is SmartMedia. So far I had 2 card totally unusable. They are used with card and only for my old Olympus 300z point and shoot camera.
Right now I have 2 pieces of 1G CF card for mu 350D.
Overall I thing CF is quite robost and can withstand rough usage unlike SM. In general keep them away from heat and moisture and shocks and some say away from kids....