This thread has made me realize how thorough I am about washing. I use a washcloth and the first things I scrub are the backs of my ears and neck, then arms, pits, torso, back, legs, tops of feet, then for last I do butt, crotch, bottoms of feet and between my toes. Then I ditch the washcloth and with just my hands I wash my bellybutton and privates.
So I guess if I missed anything it would be between my fingers and the backs of my hands.