Ways to make my smile (mouth) look bigger and wider/more defined? I'm not looking for fuller lips, just a bigger nicer smile

I am concerned about the look of my smile and is something I've always been insecure about, I am looking to make it more defined if possible my lips are quite big when I'm not smiling but when I'm smiling or laughing I get a really tight smile and makes my cheeks look chubby and I don't like the way it makes my face looks I was thinking maybe it might have more to do with the area around my mouth that I would want to change? Like make my cheeks look smaller in comparison to my mouth?