Lots of very common chunks don’t get taught early enough in many course because they are seen as somehow being examples of ‘advanced’ grammar. For instance, this common question is often left out of Elementary and Pre-Intermediate courses due to the fact that it’s the present continuous with future reference. To us, this seems crazy as What are you doing . . . ? can be taught to almost absolute beginners as a chunk for asking about plans. Look at these common variations.
What are you doing later?
What are you doing tomorrow?
What are you doing after the class?
You might initially introduce this as a genuine question to students, or when students try to ask you something similar.
You can also elicit other endings – translating into English from the students’ first language if necessary:
What are you doing at the weekend?
What are you doing tonight?
What are you doing in the holidays?
Obviously, this will create a need for some answers. The key thing for treating it as a communicative chunk at very low levels is to not expect fully grammatical replies. Single words – or short strings – like cinema, go see family, nothing, football, etc. are all acceptable responses, though we might for example ask play football or watch football? At later Elementary level and above, we might encourage or simply give grammaticalised replies such as I’m going (to go) to the cinema and I’m going to go and see my family – while still not expecting that students will use this grammar accurately.
The important thing is to make the real conversation available to students.