Stick to the perimeter of the grocery store. (regardless of what kind of diet you are on) The whole and fresh foods reside there.
Hang out in your bulk section.
Love legumes like they were your child.
Avoid anything processed and packaged, even soy.
Become familiar with herbs and spices.
Experiment with ratios of fat/carbs/protein because everyone is different.
Listen to your body more than anyone else.