This is the simplest seating chart ever and it uses materials you already have in your classroom!!
Use 1" x 2" self-stick notes to write your students' names, one per note. Lay them out freely, not in any particular order.
In pencil, on a 12” x 18” construction paper, vaguely draw the arrangement of your classroom [i.e., how many rows, how many groups or pods of desks, etc.]
Begin placing [and re-placing] your students’ self-stick notes as you plan; it is easy to “move them around” since they are stuck only temporarily. [if the “sticky” starts to wear off, resort to some tape]
Posted in a noticeable location, students can find their desk after a rearrangement; substitute teachers can easily call students by name, reorganization of one or twenty students is effortless.