For each subject requiring an essay I had worked up a stock essay that enabled me to answer any question that might come up, honed it over several months and simply reproduced it from memory come the exams. Served me well enough ...... I have recently discovered, from his autobiography, that Stephen Fry did the same thing whilst at Cambridge.
EG For English Lit you know that you will be asked to compare two poems, you also know that the poems will be a different take on the same subject and all you really need is to have a grasp of the symbolic language used (Lambs will always be a reference to Jesus for example ~ same in Art Appreciation). History will always require a comparison of two Monarchs as in "Was Henry VIII a better ruler than Queen Elizabeth I?"..... "Different but not necessarily better" just about sums it up. Leave the dates to those with retentive memories for facts and figures, they will prolly fail anyway.
In both subjects it is perfectly possible to answer the question by bullshitting your way up to the required word count and thus obtain a decent grade .... the examiners are looking for a reasoned argument not a specific answer.
So few schools teach this skill nowadays.
Mind you it doesn't work for Maths, Chemistry or Physics all of which I failed ..... dismally.