How To Not Pudding Face

As @Turjan says, there's not much you can do about the way kids look. They do tend to look a little same-ish unless extreme slider positions are used and, believe me, you probably won't like what that means for their grown up state! :confounded:
Besides, if you look around in real life you will see that kids have much softer faces than grownups.

As for making unique looking sims all I can suggest is practice. Work those sliders, and I mean all of them!