The simplest solution is not to talk unless absolutely necessary. Just because you have an opinion does not mean you need to share it with the rest of world. The rest of the world really does not care.
Make some chocolate chip cookies or brownies and share with your friends. Let the cookies or brownies do the talking.
For starters, try to find something you like about yourself :) When you're around people, *Smile more *Ask more questions as a way to get to know people better, *Listen more than you talk *accentuate the positive *relax and try to see the good *refrain from being critical ALWAYS