I had a client the other day who has been flat ironing her hair for a very long time. She came to me flat ironed--I told her she was in disguise!
I co-washed, styled and dried her and the back of her head, ear to ear, came out in beautiful spiraled ringlets. The front and sides of her head, however, were wavy/straight sprigs that stuck out and would not respond to any curly technique. I ended up doing some pin curls to blend it better but given she was also so very thin in the front, she ended up leaving discouraged and in a style that looked like she rolled out of bed.
I encouraged her that with proper care and staying away from the flat iron her hair had hope to recover and hopefully would respond the way the back did. I felt terrible that she left the salon sad about how her hair looked instead of at the very least having a style she could be happy with while her hair recovered.