I use a ceramic flat iron from ga.ma which I have owned for probably ten years, it's good! I start by combing through my hair with a wide tooth comb and add something to moisturize it, usually I use Jojoba oil to flat iron my hair. Today I used Komaza Care something hair lotion. I got this as a sample a long time ago, I managed to smudge the label, but I think it might be the coconut one since it smells like coconut. The product I great for flat ironing, it's the first time I use it like this but I gotta say I love the end result!
Anyway, back to how I go about flat ironing... I take a section about 2-3cm in width, pretty thin, comb through it with my rat tail comb (the teeth of this comb are right next to each other) and then I start flat ironing at medium length, really slowly to make sure all the hair straightens. Then I go back and start next to the scalp. Be careful not to burn yourself! I think the trick is to keep the flat iron moving. I did my hair in less than two hours. I'm not sure how long I will keep it straight, cause it's been very humid lately, and I don't like to have to re- do sections when I've already tories my hair with heat.
To sleep I comb my hair so it's like a hat around my head and pin it with a few Bobby pins if needed and of course sleep with a satin scarf.