Personally I found reading the question and redefining it in my own words then giving myself an answer, again in my own words, helps me to ensure that I always answer the question. So far this has worked well for me and leading to me achieving good marks in English. Also intro doesn't define what mark your essay will get but it is a good first impression if your intro is good you are more likely to receive a generous mark from the marker as they have a good first impression heading into the bulk of your essay. However, there have been times when someone will write an amazing intro but the rest of the essay falls flat resulting in unsatisfactory results. As such, whilst I do believe the intro in important I think the body paragraphs actually hold the most weight in deterring what range your essay is. I hope that was helpful.