Assess students. Teaching students of differing ability levels is substantially more difficult if you don't know what level each learner is on. As you start your relationship with your learners, provide multiple assessments and take note of the results. With this information, you can more adeptly rank students and identify the ones that may need additional help.
Group students differently daily. For some, the temptation to group students based on ability level and leave them in these homogenous groups proves just too challenging. While it may seem logical to put struggling students with similar-ability peers, doing so doesn't always prove beneficial. While you may sometimes want to put students with peers who have similar abilities, it is also important to create heterogeneous groups on occasion as in these groups the struggling learners can benefit from the knowledge of their advanced peers, and the advanced peers can benefit from teaching their struggling peers. That arrangement can help everyone cement their understanding of the material.
Create differentiated tasks. In education, differentiation means allowing for the differing ability levels likely present in a group of students. When creating projects or major tasks, make more than one version. Compose one project version that you feel involves skills that your students should have at their grade level, and compose another that is easier for struggling student.
Provide one-on-one remediation when necessary. Students that struggle may need additional help to understand the information that their peers can acquire more easily. Monitor your students as they learn, and if you notice that some are not getting it as well as others are, arrange to work with these struggling pupils one-on-one, pulling them aside while other students are working on projects or similar independent tasks so you can re-explain and reinforce their comprehension.