Honestly,I don't.I DC and use a good moisturizer/heat protecter, dry, and then straighten.I feel I do enough before hand to keep my hair moisturized and soft during the duration of my press.
Very good question! I'm really concerned about my ends. They feel really dry when I straighten and baggying them make them frizz up even more. I usually use pomades for the top of my head.
ORS Carrot Oil doesn't cause reversion for me. However, since transitioning I tend to rely more on co-washing and DCing to moisturize and just add my own blend of coconut and castor oils to the ends every couple of days.
The key for me is to use only a small amount of product, regardless what moisturizer it is. I haven't had problems with really any of them, but I like NTM Sik Touch, Giovanni Direct Leave-in, and sealing w/ coconut oil.
I haven't flatironed in awhile but when I did hempseed butter kept my hair very moisturized. When I flatiron again that's *exactly* what I will be using.
I'm into my second time of wearing my hair straight since I did the BC February 2006. What has really been working for me is Sweet Almond Oil. At night, I pour a small amount of it (just about the size of a nickle) in my hand, rub my hands together and lightly distribute through my hair focusing on my ends. I then put my hair up into a loose pontytail at the top of my head and tie a scarf on. My hair has been very moisturized and since SA oil is a very light oil it doesn't weigh my hair down. You should definitely try it!