How do I make sure I'm keeping my points perceptive rather than just thorough to hit the top bands/marks?

It is of course important to remain thorough throughout an essay in order to secure at least a B. However, to be perceptive is to look at the text/play as a whole during an analysis rather than just thoroughly focusing on a certain part, For instance, instead of just analysing how a character is by the end, take this opportunity to contrast or parallel how they were at the start compared to the end. Or look at the character's name, does it have a meaning, does this meaning give the readers/audience insight about the character's future? For example (say the student is studying Othello) Desdemona's name translates to "ill starred" meaning that her fate is destined to be tragic, so you can say that despite her joyful tone at the start of the play Shakespeare foreshadows through her name that by act 5 she'll be faced with doom. Then you can go on to explore why Shakespeare may have foreshadowed this to us. See what I did there? I didn't just thoroughly look into Desdemona's tragic end, I enhanced my answer by seeing if the meaning of her name links to her end and when I found out it did, I took advantage by drawing in authorial methods by emphasising Shakespeare's intentions for this character from the start to finish of this play.