Do not dress casually unless the interviewer expressly asks you to do so. Even then, lean to the conservative side. Make sure your shoes are well shined and unscuffed. This may be a distraction or even an irritant to an interviewer. Cover any visible tattoos.
Clip fingernails short and be sure they are clean.
Remove any earrings days before the interview. Hair should be clean, short and combed. Wear a freshly pressed, conservative blouse of classic cut, not low cut. Make sure your slip does not show at the kick pleat. Nylons should be skin tone.