My dietary rules:
~to get a bare minimum of 20 grams of fiber per day. (I usually average around 30-35!!!)
~to get in 100% RDA of calcium each day (I do this with soymilk, yogurt, energy bars...if I run a little short I take a supplement that day.)
~to eat a MINIMUM of 5 servings of fruits and/or veggies per day. (I have been averaging about 6-8 per day lately.)
~I limit my coffee intake to 1 cup per day.
~I drink a MINIMUM of 4 glasses of water a day...but I average 6-8.
~I limit my intake of simple carbs-and try to eat fruits/veggies/whole grains instead.
~Not a "diet" rule so much...but I also record my exercise in my journaling. I have proudly walked well over 100 miles so far this year, and have belly danced for almost 40 hours.

I haven't even went into my recordings for strength training and yoga practice!
I find that when I aim for these health and nutrition goals in my diet-that I have "less" room in my daily calorie intake for "junk".