Treating dry skin can be a constant process, especially in the winter. Sometimes dry skin reflects a health problem, especially thyroid disease. More often it is inherited, seasonal, and/or related to advanced age.
Moisturizing is at the cornerstone of treating dry skin. Because dry skin is also often sensitive skin, the kind of moisturizer sometimes makes a big difference. To be on the safe side, a moisturizer without many additives or fragrances is the best bet. Some good choices include Cetaphil, Curel, Eucerin, Neutrogena, shea butter.
Unfortunately “unscented” usually means there are masking fragrances included. Even “fragrance free” products sometimes have “essential oils” (like rosemary oil, or lavender oil, for instance) that the company is using as emollients.
Cost does not always reflect value. Some really inexpensive and effective choices include Crisco and Vaseline (!). Acidification helps dry skin heal, and so acid mantle cream, Lachydrin and Carmol are good medicated creams.
A technique that really helps dry skin, especially if you are really itchy, is the following: soak in a comfortably warm/hot tub for 15-20 minutes. Do not use soap, which is very drying. When you dry off, just pat dry so you don’t irritate your skin. Then immediately moisturize. This technique allows your dead skin to swell, and gently break the bonds with your living skin.