Hey Tracheotomy! Welcome to ATAR Notes.

What's your annotation technique at the moment?
I think the first step is to know what you're looking for. Pages 17-18 of the
study design list all of the metalanguage you need to know quite nicely.

Once (or if) you're comfortable with all of those terms, why not try to annotate 5, 10, 15 different texts? They could be newspaper articles, ads - whatever you can find. Just annotate - don't bother writing the actual analytical commentary.
I think it'll probably just come with practice.
Also, something I liked to do was use a different colour highlighter for each subsystem. So like, purple for discourse, yellow for semantics, and whatever else. This gave a better indication of what subsystems I should actually discuss in the analytical commentary.

But yeah, once you know the features you're looking for really well, you can actively search for them. And this is probably easier than just reading the text and hoping for the best.
