Oh thank you my dear! Ok there’s only one reason for that. And it’s thirst. And years of practice. It’ll always come out sizzlin. I had the same feel years ago but I never get the faces that I picture right (proportion and anatomy wise) so, it takes practice! 

Basically, if you feel something (whether thirst, aggressiveness, sadness, or happiness) they just come out as your drawing’s expression. So ye, they mostly work when I just feel like drawing them but I try to push it bc it became a style I usually do.