Just as with blow drying it's up to the individual. It's also ok to flat iron or curl your hair everyday if using the proper tools and procedures. Make sure your hair is 100% dry before you put any hot tools on it. This is very important. Your hair will sizzle and burn if any moisture is left in it. Along with blow drying ,when you use a flatiron or curling iron you want to always use a heat protector before you use hot tools. Selecting the right temperature for your irons is very important. If you have fine hair choose a lower heat setting. If you have coarse hair use a higher setting.Never leave your irons on too long. You will short out the iron. Having professional irons makes a difference on your hair. Just as with a blow dryer ,whether they are ceramic, ionic or tourmaline they still need to be used correctly. Comb through your hair before using any iron to ensure even curl pattern and no kinks. Use even pressure from root to end without stopping to get smooth effect. The smaller the sections you use will give you a more flat, weightless look. Use a shine serum and hairspray to lock in your look. Keep your irons clean from product and dirt and they will last longer and always let your irons cool before putting away. If your hair feels dry or is breaking,turn down the heat setting and take a break from using the hot tools.