Wear clothes that fit your body as it is now. That's it.
A seemingly simple fix. Yet people resist this all the time, either by hiding in baggy clothing or continuing to wear things that are too tight because they can't bear the thought of going up a size or two. They cling on to hope that they will eventually achieve the body size/shape they desire and therefore hold off on buying new clothing until then, except that time never comes.
It's as if the number on the clothing is a measure of a person's self worth. It's not — unless we give it that power. A number is just a number. And when it comes to clothing it's a pretty arbitrary number. Different brands, and even styles within brands, will fit a person's body differently. You may wear totally different sizes in different brands. And it doesn't matter. What does matter is that the clothing fits you. It is not your job to fit the clothing; it's the clothing's job to fit you.
You will feel your best in clothing that fits your body as it is right now, regardless of the clothing size or the way you feel about your body shape/size. Anyone who has ever watched an episode of What Not to Wear knows that this is true. In so many episodes the person's body image was completely transformed through the process of finding clothing that fit their size and body type. That's pretty powerful stuff.
So how about some retail therapy? It just might do your body image and self esteem wonders.