elaborate when your descriptions in the essay are vague. Elaborative interrogation and self-explanation are both very effective strategies to improve learning. just ask "why"
I normally check the places where I only touch on a subject for one or two sentences. Make sure to use plenty of engaging adjectives; I would even recommend scanning a dictionary to find some unique words which will impress your teacher.
Did your instructor leave any comments on what you could have done better? Have you gotten a peer review? If someone has already pointed out the weak spots in your essay, work on those to strengthen them.
Maybe add in a few quotations or evidence where further context is needed.
