Use a boar bristle brush. While you should avoid using most types of brushes, a boar bristle brush is the one exception. This brush is made with special natural bristles that mimic the texture of your hair. It is used specifically to pull your hair's oils from the scalp all the way down to the tips, without causing any damage. It's a good investment if your hair is bone-dry and you want to pull out all the stops to rejuvenate it. Here's how to use the brush:
Wait until the night before you plan to wash your hair, since that's when your roots will have plenty of oil.
Comb out any tangles using a wide-toothed comb.
Pull the brush through your hair from your scalp down to the tips. Repeat several times over the same section of hair before moving on.
Continue until you've brushed out all of your hair. It should feel soft and silky when you're finished. Wait an hour or two before shampooing.