The problem is that we're too busy picking ourselves apart, comparing ourselves to others, and imagining how much better we would feel with "improvements". Accept and make yourself start believing that you look awesome exactly how you are. It's never going to be the easiest thing in the world to love the way you look. Just start small. Stop looking in the mirror, tilting your head, and pondering "Hm, I would look better with _______/I wish I didn't have _______/I wish I did have _______/I don't like _______/If only _______". (< The blanks indicating what you, personally, would insert there) No. Start by saying "no". No, I am not going to pick myself apart. I am not going to wish for something else. I am not going to compare myself to what I think is better. I am not going to belittle myself. Start looking in the mirror, smiling super big--even when you don't want to--and thinking "I like _______/It's cool that I have _______/I look great because _______". If you have trouble doing that, then start by imagining that you have an awesome friend who has almost your exact body or face. Now, would you ever say to this friend, "You're fat", "You're ugly", "I hate how your _______ looks", or "I would like you better if you had _______". I'm going to assume that you would not say those things to any of your friends. So, why on earth would you say that about yourself?
The following is for people who are bullied about their appearance...Please do not take to heart anything that those people said to you. They were lying. Whether it's because they wanted a reason to pick on you, or they themselves are insecure, whatever they said is simply not true. Everyone is insecure in some way, but unfortunately some people do not know how to handle that insecurity well. So, in order to make themselves feel better, they make someone else feel awful, and so on and so forth. It's a vicious cycle. Be the one to stop that cycle. As hard as it may be, don't retaliate; instead, encourage others that they are beautiful and special too, and maybe we can break that cycle.
At the end of the day though, outward appearance doesn't matter a bit anyway. I know; this is also hard to accept and believe. It is true though. Your heart is where the darkness clouds up, negative thoughts set in, and you fall apart; or, it can be where light radiates, lovely thoughts blossom, and you are made alive. Only God can do the latter, by the way. No matter what you look like on the outside or how you see yourself, you are dead inside until you allow Jesus to live there. Once He is residing in you, you are made alive, washed clean, and He sees you as beautiful. Even if you don't accept Him, He still cares for you. God is the creator of beautiful things, and let me tell you something: He created you. The same God who made the galaxies, planets, flower fields, mountains, valleys, rivers, beaches, and sunsets, also crafted you.
Don't forget to remind others of how beautiful--or handsome--they are. Every day, someone you encounter will need that reminder more than anything else, and you can be the one to give it to them. Practice viewing yourself positively as well--it will pay off. Just remember in the process that the significance of what your face and body looks like cannot compare to the significance of what your heart and soul look like.
"I praise You, for I am fearfully and wonderfully made; Your works are wonderful, I know that full well." ~Psalm 139:14~
"For the Lord sees not as man sees; man looks on the outward appearance, but the Lord looks on the heart." ~1 Samuel 16:7b~