To go all out as a killer clown, take a cue from vlogger ThuggeeDee. The fake blood, heavy blush and teeny eyebrows will definitely give your face that fear factor. And if you want to take a pass on the blood, you can still create the heavy makeup look.
"Nicer the man, meaner the clown" -- Winston, Pilo's Family Circus. The idea is nice guys are transformed when hidden under makeup... made me think of Dawn as the epitome of good-gone-mean. (And not that smug way some guys say "I make good girls go bad". That really pisses her off). It's basically the id vs superego.