Hi RizosMio, I apologize for the novel in advance
The only type of heat I have used has been in between sewins. I have done hot oil treatments and deep conditioned under a hooded dryer with a plastic cap and I believe I have used a handheld blow dryer with the diffuser maybe 2-3 times since my big chop, mainly to try out styling products on my curls before they would go back into a sewin for a few months. Other than that no. I don't plan on flat ironing my natural hair at all when I do wear it out, or at least night while my goal is getting and retaining length. Before I decided to go natural I can tell you I have never in my life had an issue with heat damage or breakage (other than after getting color with one stylist followed by horrible drying Mizani products, my hair had to be cut in drastic layers).
When I did flat iron my relaxed hair I only used Kera Care's Cream Press, I love it and pretty much everything they make! If I ever do flat iron my natural hair that is what I will use as well, unless my hair says no. I prefer it because it actually coats & melts into your your hair as apposed to spray "Protectants" that sit on your hair. But for the most part I usually flat ironed my hair for the week after I washed conditioned and deep conditioned, so moisture was locked into my hair to begin with. At night I would wrap my hair. I never liked bone straight, flat, thin looking flat ironed relaxed hair (which is usually how it looked after my salon relaxer) so I was never obsessed with heat to that extent.
I always hated how stylists killed the body my hair had after blow drying when they flat ironed, going over a piece 3-4 times after I just had a relaxer!! I would go straight home rewash, condition, add either Dudley's Fantastic Body Texturizing Setting Lotion or Dudley's Styling Foam Setting Lotion to my wet hair for body and then comb through my hair with a wide tooth comb & a hand held blow dryer on low-med heat. My hair would be nice and thick and big, but manageable because of the relaxer.
Then I would flat iron in somewhat med-sized sections (don't like bone straight hair remember) and used the KC Press Cream mainly to just give my strands a smooth look and to give the ends a slight curl under. Sometimes I would throw a couple spiral curls in just for effect.
Be Careful with the Cream Press you can use too much of the product and get heavy hair but if you use the right amount on each section at a time the results are amazing and it lasts a long time. I would always get compliments, people would always wonder where I got my hair done lol!
Rub it into your hands like lotion and coat on both sides of your hair, on top and underneath, wherever the flat iron plates will touch.
KeraCare Creme Press, Cream Press - Avlon Hair Care
Dudley's Fantastic Body Texturizing Setting Lotion - Dudley's Q
Dudley's Styling Foam Setting Lotion - Dudley's Q
I did own this flat iron (in Pink 1") until I gave it away (because I bought a new one) but it worked great.
Sedu Revolution Tourmaline Ionic Styling Iron 1 | Folica.com
Now I own this one (in Purple) in 1"
Solia Tourmaline Ceramic Ion Flat Iron (1-1/4") plus free heat proof pouch | Folica.com
They are both wonderful. My nitpick about flat irons is the ones that snag your hair in the corner edges, to where you literally see stands of your hair in the edge of the flat iron
Neither of the 2 above do this. The last salon I went to they used a ceramic one that did, nearly drove me up a wall. I did originally own a Sedu that did do that, not too long after Sedu came out with one that no longer did
but I'd already moved on to Solia. I also have a cute mini Solia flat iron I believe it's like 1/2" I got it as a gift when I purchased a regular sized one, and it works great. I have used it to add spirals and to just curl my bangs when I didn't want to heat up the mother. All in all they are all great and they all heat up super quick, like 1 minute tops they are ready, even if you are not yet!
My original & first flat iron ( I still own it)
Sedu Pro Ionic Ceramic Tourmaline Flat Iron (1 1/2") with free heat proof pouch | Folica.com