The kind of materials you could and perhaps also should use depends on the educational level of your students. It is clear that you university students are to be taught in different way than perhaps less educated adults.

Unfortunately, I feel unable to give you more concrete and precise advice - your input lacks details on the age, educational, cultural and linguistic background of your students.

However, never think any material you may use may be too "babyish" from the beginning. Instead, try out several kinds of materials if you have them, and see how they respond to them. Only then adjust the materials you are using.

Good luck!