Incorporate theory. At the college level, students should be exposed to literary theory. If your department has a specific course meant to introduce students to theory, then you may be able to request that students incorporate theory into papers or presentations. If not, then you may need to provide some instruction to help students understand and use literary theory.
For example, you could require students to craft discussion questions that incorporate a specific type of literary theory, such as feminist, psychoanalytic, or Marxist theory. Or, you could assign different schools of literary theory to individual students or small groups and require them to develop an analysis of a text using that theory.