Tier 1, the first level of instruction in the RtI (Response to Intervention) framework, is designed to meet the needs of 80% of students within the regular classroom. The only way to accomplish this goal is to use differentiation. Differentiation is not a singular process; it is rather a complicated process of adapting instructional strategies so that "all" students can be successful. Differentiation requires that teachers adjust their content (what they teach), process (activities that help students understand the content), product (how the students demonstrate their acquisition of the knowledge) and the learning environment according to students' readiness (where they are in the continuum of learning), learning styles (how the students learn best), or interests. With the continued focus of Common Core Standards, adjusting the content may be difficult for a teacher to accomplish. Therefore, teachers may want to concentrate their efforts in differentiation in the process, product, learning styles and learning environment. For twice-exceptional students, teachers need to get to know their students from multiple perspectives. They need to use their pre-assessment data to identify areas in the curriculum where students may be above grade level as well as to identify areas where students may have holes in skill sets. They can also get to know their students better by using information from Multiple Intelligence assessments, learning styles and interest inventories, or surveys on other factors that impact student learning. Many teachers give pre-assessments, learning style or multiple intelligence surveys, and interest inventories, but few of them adjust their instruction based on this information. In this article, the author discusses how this should work for "all" students, including twice-exceptional students. Differentiation might be difficult for teachers to learn how to do, but it is a required skill for teachers to use effectively if they want their students to show growth in their learning. Once a teacher learns how to differentiate, it becomes the only way to plan instruction.