Like top of foot, knee, crotch, kidneys, diaphragm, throat, eyes, ears, nose.
Only see the targets. Only see the targets. Only see the targets.
Then run like hell.
Even ear claps with cupped hands are pretty nasty. Wouldnt expect an average person to do them well, but if you did them really well, on both ears you might kill the person.
My personal ones would be doslocate elbow, throat, groin, eyes, or if desperate, Rick Grimes artery bite.