Could you help me simplify my diet?

Life is busy, and its about to get busier for the next few months. I’ve been having trouble figuring out what I should be eating; it is usually an afterthought.

Right now I usually eat a meal bar or a parfait in the morning, a power smoothie (protein, vitamins, and fiber) for lunch, then I usually end up eating out for dinner. All together my diet is probably expensive, with less-than-ideal nutrition.

How can I fit a balanced, affordable, easy, healthy diet that will feed my body and mind? Shopping tips?