To get the smoothing effect, start with freshly shampooed hair. Gently squeeze or towel out excess water so the balm is not immediately diluted. Apply it to the mid-lengths and ends, not the roots, especially if your scalp tends to get oily quickly. The roots usually do not need this kind of conditioning, and applying it there can make the hair look flat.
Work the balm through the lengths with your fingers or a wide-tooth comb so every strand is lightly coated. How much you need depends on the length and porosity of your hair: fine hair usually needs less, while long or very porous lengths may need a little more. Start with a small amount and add more only if the hair still feels rough.
Leave the balm on briefly, then rinse thoroughly. It is a rinse-out product, not a leave-in conditioner, so do not skip the rinsing step. Rinsing with lukewarm or cool water can help the cuticle lie flatter, but the main smoothing work is done by the oils and the conditioning film left on the hair. After rinsing, gently squeeze out water and style as usual.