How to tighten the area around marionette lines and jowls so my smile looks more like the one in the above pic? (Photos)

I’m 28 years old. My weight does fluctuate, but the area in my lower face and jawline always seem to hold on to fat (extra skin?) which makes me look older than I am. I also feel that my facial features could be more balanced between chin, mouth, and nose, but I’m not sure what I should start with to achieve that result. My teeth are pretty small and I would like Vaneers some day but would like to see if there is anything I can do in the meantime.