I have been doing it for about 2 years now, rather easily. Here is a broad picture of what I do:
Mon., Tue., Wed. - eat restricted carbs througout the day, basically only allowing for veggie and fiber carbs or tag along carbs that come with the meat flavoring. Meals are almost always under 20g carbs, usually around 10-15g carbs (subtracting fiber). Eat huge post-workout meal of whatever I want (within BBing reason), usually around 100g carbs or so and around 80g protein.
Thur. - eat moderate calories, moderate carbs. I very loosely shoot for the 40/30/30.
Fri., Sat. - same as M/T/W.
Sunday - eat like a hog. Donuts, fast-food, ice cream, whatever the hell I want. I go for high calorie, and avoid protein, if possible.
This is the basic template I follow. It has allowed me to consistently (albeit slowly) lose fat while gaining muscle for a long time now. I tweak the little nuances of my diet based on present goals, i.e. up the total calories if I want to concentrate more on gaining muscle or opposite if I want to lose more fat.
It's not the fastest way to gain muscle, or the fastest way to lose fat, but I'm not a competitive body builder. I also couldn't stand gaining fat on a bulking cycle, then having a bitch of a time losing the fat on a cutting cycle, but never quite getting to the point I wanted to get to because I either couldn't lose enough fat in the time-alotted, or I couldn't stand the muscle loss. For the regular Joe that wants to look spectacular, this is the best I could come up with for someone that wants to look and feel good all year round. I have felt in the best shape of my life at almost any given time in the last 2 years. The "plan" also fits well into every day life. The fact that I haven't really hit a plateau floors me. Obviously, it works better on AS, but I still can make crazy gains without. As a matter of fact, right now I've delayed my next cycle 3 weeks, because I went into "cycle-mode" of being high-intensity, but without the AS and have been very surprised at my gains. The only time this plan doesn't work for me is when I get lazy and don't stick to the diet or workouts.
My cholesterol level droped from 179 to 123 (in 2 years) doing this. I wasn't even trying to drop it.
If you want me to go into detail on my reasoning for some of the stuff, let me know. I can also go into detail on some more of the "tricks" I use, although I bet you know most of them - it's just a matter of doing them.
I plan on eating like this for the rest of my life, by the way.