Is your hair naturally white or do you use chemicals on it?  Hair dries out for several reasons. Certain seasonal changes show in our hair through appearance but also through touch.  Conditioners do help in both cases but even so, hair can still look and feel dry.  Generally speaking, the lighter the hair the more dry it can appear, but not always.  Shampoo your hair with a clarifying shampoo and follow it with a moisturizing shampoo then a good sealer (ascetic acid ingredient) that helps close the cuticle down.

Either allow it to dry naturally or blow it dry. Once hair is completely dry, you can use BioSilk Silk Therapy or another silk building product such as Chi, Bain de Terre, etc., and lightly iron it with a curling or flat iron. This will not cause further damaging of the hair unless you turn it up too high.  Instead, this helps to close the cuticle down further which naturally promotes shine. 

Hair sometimes looks dry because we lack the right kinds of oils in our diets. Olives, walnuts, almonds and such foods help to promote good hair health. If you tend to jump on the weight loss diet bandwagon, your hair will surely reflect this.  Shampooing too often and not enough can add to the feeling and appearance of dryness. Whether your hair is naturally white or bleached, it will tend to grab and show the toxins in our environment more compromising shine.  Also, white hair that tends to yellow and get a rough feeling can indicate a thyroid problem so if this is the case for you, see an endocrinologist.  Hope this helps. If it doesn't, contact a hair professional and have her/him show you a way to help build shine into your hair.  Good luck.