Since everything is energy vibrating at various frequencies, your body is a set of vibrational frequencies to which you match and are made from. When you look at another person's physical appearance, you are looking at the vibrational frequencies at which they are vibrating.
A person's vibrational frequency is their appearance and it indicates how they feel since the vibrations at which they vibrate at depict how they feel. If you are attracted to a person's appearance, you find the vibrational frequencies at which they vibrate to be desirable, but if you are not attracted to a person's appearance, you do not find the vibrational frequencies at which they vibrate to be desirable.
To improve your appearance, all you must do is focus on improving the way you feel and as you improve the way you feel, others will find the vibrational frequencies your appearance matches to be more desirable as a result.