Photo: Robert Trachtenberg

A: In spite of the old biceps-building 100-strokes-per-night advice, you should brush your hair minimally. Routine brushing damages the outer layer, or cuticle, of the strands, which can make hair look lusterless and frizzy, says Paradi Mirmirani, MD, assistant professor of dermatology at the University of California, San Francisco; better to use a comb with widely spaced teeth and smooth tips. But if you like the way a good brushing feels (as I do), avoid boar bristles, which generate damaging friction; instead, choose a model with plastic, ball-tipped bristles. The Goody Ouchless Cushion Brush ($7.50; drugstores) is a fine choice.

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