The only problem i have with flatironing is i need for my hair to have LESS body----I have to start doing things that will give me less volume
Some things that i've noticed are:
Hair flatirons better when your hair is dryed SMOOTH as possible. I used to airdry my hair in a rough ponytail because it didnt like combing it while wet. But when your hair drys smooth, your hair looks much better then if you wait till it drys, detangles it, then flatirons. I've found that for people with difficult hair setting foams work well to keep the hair smooth.
Hair looks much silkier flatironed when your hair is moisturized from your conditoner. If you havent found the conditoner that leaves your hair soft and moisturized after rinsing, then try to do the "little product as possible" then your hair will not feel as silky as it could. Silicon Mix was that conditoner for me---your hair also seems to stay staight longer.
You have to find the right product for you----Heat protectants, Serums, pressing oils, oilsheen ect. seem to make all the difference. For me personally there was only one heat protecant that actually made my hair shine, and i found that pressing oils actually make my hair sleeker, smoother and silkier (but it could be because im trying to achive less volume & fluffy so i need something heavier)
I also think heat protectants, serums, and pressing oils work better when you put them on wet hair.
I also think for some people their hair looks better when dried with some sort of heat---like a rollerset or blowdry.