Plan, plan, plan!
Make sure you take time to plan your essay before you start to write it. That way, you'll know exactly what you're going to say and then can think clearly about how you can communicate your point clearly and to a high level to the examiner. Your plan doesn't have to be extensive, but can help you clearly and methodically think about the question, which will make your answer coherent, and flow between each paragraph.
To avoid feature spotting, it's a good idea to think about why the author has decided to use that certain feature.
For example,
Feature: Pun in a headline
Why?: To add comedy to the article, make the headline stand out, or thought provoking, make readers want to pick up the article and read it.
It's good to remember this by P E E
P: Point
E: Expansion
and E: Example
You make your point, give an explanation of why you think the writer used this and then give an example.
Make sure your essay has a good structure to get those all important top marks. Make each point have its own paragraph. The introduction should just briefly summarise what you're going to talk about. Each paragraphy should delve into your points into great detail, and the the conclusion should summarise what you've discussed.
In comparative essays, make sure you group together similarities of both articles into the same paragraph. I.e Article 1 and 2 both use puns, both Article 1 uses them to convey _______, yet Article 2 uses them like ______. I feel this is because ___________, you can see this because Article 1 quote.