What is the correct way to use a deep conditioner?

In my shower I have two deep conditioners: Miricle 7 & Aussie 3-Minute Miracle. They are both very good. But Im not sure in useing them the right way, Do you shampoo, conditon, then deep conditon? or just use the deep conditoner as a conditoner? I only deep condition my hair about twice a week, Is that enough? I have dry frizzy, partially damaged hair. How often should I deep condition it?