Hi. I don't put any product on the roots. Seems to give me better root volume. My hair's fine, non porous (so product just sits on top of it), and very curly (I guess you'd say 3b, though I don't think those categories mean much). Getting weighed down is a major issue for me. Too much product (which is almost none at all)=greasy, flat hair. Too little product=great curl with frizz. Less product is always better for me for not getting weighed down - more than a dime sized amount makes me really oily. Rinsing upside down and finishing with cool water helps too. Still experimenting with types of product and when to put it in. Soaking wet seems best, but then my hair takes *hours* to dry (it's that nonporous thing). It's all an ongoing experiment...
-Porosity an ongoing mystery, fine texture
-Hair likes: light conditioners and light protein, light cones
-Hair dislikes: oils, heavy conditioners, and glycerin

-Co-wash/conditioner: Elucence Moisture
-DPT (rarely): Ion Effective Care
-Styling products: Elucence as a leave-in and (cone alert) Giovanni Frizz Be Gone