It is difficult to recommend something certain because I do not know your topic and subject for the test, and I did not see your current work to read it and find the possible mistakes. Could you be more detailed with the question for the best answers? 🙂
However, in general, I can say, from my own experience with essay writing, that it is important to avoid some common but serious mistakes to improve any kind of work of this type.
The most common in their case among students are:
– poor understanding of all of your task / subject
– no clear subject and thesis, as well as a plan for the whole job
– lack of good scientific / informational resources according to your subject
– poor vocabulary, style and grammar
– formatting errors
– weak introduction and conclusion
In addition, the important problem is the lack of controls and editions for your work, you must give him enough time to check it and check it carefully at least several times. A new perspective from other people can also be very useful because they can see the mistakes that are hidden from you. Your parents and friends can help you. There are also editorial professionals at https://homeworkneeded.com/ who can also help you improve your text.