Slouch and your stomach pooches. Straighten up, and your tummy looks trimmer without breaking a sweat! For better posture, align your ears over your shoulders, shoulders over hips, hips over knees, and knees over ankles. Keep your shoulders open like a shirt on a hanger, not one draped on a peg. Draw your navel to your spine. Not least, keep your weight even on the balls of your feet and your heels.