Treating fine frizzy hair usually starts with choosing the right shampoo and conditioner. Look for products that are specifically designed for frizzy hair, and make sure to use a lightweight, moisturizing formula. After shampooing and conditioning, use a leave-in conditioner or serum to help reduce frizz and protect against humidity. When styling, avoid heat tools if possible, and opt for air-drying or diffusing. If you must use heat tools, make sure to apply a heat protectant first. Finally, try to limit washing to just a few times a week, and use a dry shampoo on the days in between to help absorb oil and add volume.