First you would want to shampoo and condition your hair with an anti-frizz shampoo since curly hair tends to get frizzy. Use lukewarm water to rinse your strands, since hot water can strip your hair of its natural oils, which only exacerbates frizz. After washing your hair, towel dry your hair with a microfiber cloth or a t-shirt, both of which will be gentler on strands than a cotton bath towel.
The best way to straighten your hair with the least amount of stress is to use a blow dryer to dry your hair before putting a flat iron onto your hair. To make things easier you can section off your hair with a few clips and a round brush to dry one section at a time. After your hair is fully dry, you can use a flat iron to straighten your hair in small sections. You want to make sure you’re ironing small enough sections that you only one or two swipes.
After you’re done straightening your hair, you should use a small amount of hair spray as too much product will weigh your hair down. Some things to remember is to make sure you are using a flat iron that has a temperature control. Also, make sure you are not using too much products before you start straightening your hair, all you need is a heat protectant at most. Make sure you are not sectioning your hair too large, requiring you to do more than one or two swipes, and damaging your hair.