Since it is a how to, I think breeding would give you a good amount of substance to utilize in your speech. If breeding alone doesn't give you enough material to talk about, you can add on neonatal care and raising them to adulthood, or selling age. you could also throw in something about genetics and selective breeding.
Other ideas:
-how to propagate/cultivate and or maintain plants for chameleon vivariums.
-starting and maintaining insect colonies for your chams
-Creating a complete setup like housing, decor, lighting, hydration, etc.
- how to choose an exotic pet or pet reptile to fit your lifestyle
-panther care in general
-any chameleon related DIY project, choose one that is not so chameleon specific that your audience can understand.
