Grooming is the first thing. For example, being clean shaven perks up your appearance and wearing clean and wrinkle free clothes give a much better impression than not doing so. Sparkling white teeth and fresh breath are important as well. Eating in a healthful way is best for your appearance as well as your health. Be sure to focus on eating lean proteins, veggies, nuts, seeds and fruits and drink lots of water. Avoid man made foods and sugars whenever possible to avoid weight gain and health problems.
Pay attention to the types and colors of clothing you choose. Fit and color can make a huge difference in your appearance. For instance, avoid wearing colors that are close to your skin color and choose colors that complement your personality and skin color. Avoid clothes that you have to constantly tug at or adjust, these are clear signs they don't fit you properly and do not enhance your appearance.