How should i smile. and pose?

ok, so i have a lopsided smile with perfect teeth. i hate my smile, its like straight, not curved up ward. i have smile lines and where shouldi put my tounge? when i smile. also, when i smile only my top teeth show. its so dumb,and its not very pretty. i wish i had a better one. any of you have anyways to pose and where to put my toungue and stufff? PLEASE HELP!