A gentler shampoo, of course! As long as you aren't using cones, a sulfate free shampoo that's gentle can work; but even if you don't, sometimes your hair wants the sulfates. No two people's hair ('cept for identical twins, of course) is the same.

I'm an exception on these boards. My hair can handle a moderate amount of cones and can also tolerate sulfate shampoos (though the trick is getting the right ones for the right seasons).