An important aspect of a balanced diet is eating a variety of foods. Since each food has a different balance of nutrients, you want to get as many different kinds as you can.
For example, you can use all kinds of different grains: brown rice, quinoa, millet, amaranth, barley, whole wheat, rye, kamut, spelt, etc.
And you can use all kinds of different greens: lettuce, kale, bok choy, chard, mizuna, spinach, mustard, alfalfa sprouts, and so on.
Variety doesn’t have to happen all in the same meal or day. Try to grab different fruits and vegetables as they come in season, and vary your grocery list each week.