When you are using a hair dryer, you should take extra time to dry it on the cool setting. The cool setting on your hair dryer will cause significantly less damage to your hair, than if you dry it with very hot air. Hot air will cause drying to the hair.
Avoid products that are not formulated for your specific hair type. Various hair care products exist on the market, and within those are variations for each type of hair, whether oily, dry, sun-damaged or even, colored. Making the wrong decision in products can have negative effects on your hair and make your existing issues worse.