I have a PhD in Russian from Columbia University, and 31 years of university-level teaching experience. Now that I'm a Professor Emeritus, I've became an art educator and language tutor. I've tutored people who were native speakers of French, Spanish, German, and Hungarian, among European languages; and of Japanese, Korean, and Chinese, among Asian languages.
And, actually, tutoring for SAT Prep and helping people improve their grades in high school English is not so different from that. When I do that kind of tutoring, I emphasize features of the very complicated English verb system such as colloquial phrasal verbs and their more formal equivalents ("to go back"/"to return").
Of course, every student is different, and each teaching situation is different, so I bring to each session a prepared lesson that both reviews the previous lesson and works on new problems and ideas.