In theory it sounds pretty easy. You eat more fruits and vegetables by "sneaking" them into your daily diet without being obvious. But it takes work. One idea is to buy more veggies than usual and leave them out on the kitchen counter so you'll be more likely to include them in your cooking (or snacking).
A better idea is to combine them with other foods. Cauliflower can be pureed in a blender and mixed into your mashed potatoes without a noticeable change in texture or taste. Grated carrots and/or chopped spinach can also be added to your spaghetti sauce (in the skillet) with much the same effect. A registered dietician wrote a book last year called, Stealth Health to guide people in this process. It should still be available on amazon.com.