Re: how to use glossing serum?
put the serum on damp hair, then let your hair air dry or blowdry it. then use the straightening iron. always put product on your hair before using any type of iron, and always iron dry hair only. irons can do a lot of damage to hair if not used properly.
also, if you plan on using a serum (or other silicone product) on a regular basis, remember to use a clarifying shampoo at least once a month, or ideally once a week, to remove buildup. silicone products build up in hair very easily and can cause breakage.