The mission of most writing centers is to cultivate effective and independent writers. However, in sessions with students from culturally and linguistically diverse backgrounds, tutors tend to make direct edits on their writing products despite writing center policies that discourage such practices and encourage process-oriented writing instruction (Cheatle, 2017; Kim, 2018). One cause for this problem might be the minimal tutor training of specific techniques to best support multilingual students' writing development. The focus of this article is a practice to support writing tutors called "autonomy-supportive" instructional strategies (Reeve & Jang, 2006), which are designed to nurture students' inner motivational resources. The authors integrated the model of autonomy-supportive instructional strategies with the existing literature on English language teaching and writing center practices. In addition, they incorporated reflections on our teaching experiences with adult multilingual writers. They conclude by presenting 11 hypothesized autonomy-supportive tutoring strategies to use among multilingual student-writers and a writing tutor handbook that encompasses their synthesis of the literature and their experiences.