For visual texts, a few common techniques you can use are salience (the part of the image which is prominent), framing, gaze (if there is a human in the picture), symbolism.
For written texts, it really depends on the style of text (poem, essay, recount, description, etc) so they'll be many more possible techniques you could use, but some ones to use if you're struggling to find any are things like perspective (1st person, 2nd person, 3rd person), imagery (very simple but can be effective if described properly), symbolism, metaphors (tend to be very common).
Honestly, they don't look at the sophistication of the actual techniques that much. What markers are more focused on is how you can link it back to the question, and most importantly, the Common Module syllabus and what it entails.