I have poofy wavy hair and my hair is thick, what can i do to make it straight and flat? Any hairstyle ideas?

I have poofy wavy thick hair. its really poofy especially after the shower. i use chi shampoo and comditioner i brush my hair after im done washing it in the shower. i then towel dryy and then let it air dry. I want my haair to be straight and flat, but i dont want to staighten it, thin it out, or get a brazzilian blow out becuase of the damadge. my hair is a little below my shoulder and i dont have bangs. Any idea what i can do to get flat straight hair?? any hairstyle ideas??