Most people who look for persuasive techniques in LA end up looking at mediocre LA score (or worse, English study score) come results day.
Look for what language, design, pictures (etc.) the author uses to persuade their audience. Sure, most of what you analyse won't actually be /that/ persuasive to you, so look for what the author does to support their contention or to pull the reader to their side. Dumb yourself down if you have to, or pretend you are part of the desired audience/readership. Whatever helps you to see the article in that light (the latter is what I tended to do).
I find it is much more effective to find some sentences that are particularly good to analyse and then pull it apart and see what individual effects those words have. Then, link that sort of effect to other instances where the author has done that, I have no problem in going against chronological order especially if the link helps the reader to recall something the author said before or something # y o l o.
If you do that, the examiner knows that you've actually thought about what the author has done through the whole piece, rather than saying some generic crap like "X presents statistics regarding ISSUE Y to convey to the reader that the issue that his stance on the issue is well supported and that he very knowledgeable, in fact it might almost appear to the reader that X is a gentleman and a scholar. Now later in this paragraph..." Anyone can pull something like that out of an English Study guide and it is NOT original. People who look for certain "techniques" all tend to write the same general bullshit (more or less), and end up namedropping techniques in an attempt to impress and examiner.
Sure, there's nothing wrong with namedropping if you actually know what you're doing and are analysing it well, but my word of caution is that you shouldn't read an article looking for techniques, you should be looking for persuasion, things that move the reader, nice wordplay, and so forth, if there is a defined technique in that then that's fantastic, but if not then that's great too, just analyse the shit out of it anyway!
Not sure why I wrote all of that, but it felt mildly relevant to the topic.
(disclaimer: I'm not an amazing English student, check with Brendo or someone before following my advice)