Firstly, you need to plan out what you are going to write in your essay. Divide time smartly. Map out ideas in your head beforehand so you don't waste time thinking at the moment.
Secondly, think about the proper structure of your essay as soon as you read the topic. Think about a few major headings that can be further sub-divided into sub-headings so you can easily format your essay. Organize your essay and don't stray away from your own point or the topic.
Thirdly, Use good quotes that go well with your topic. This can only be done if you read books, newspapers, magazines, and other educational scriptts. Reading is definitely a basis for improving your language and building a good essay.
Fourth, be creative and original in the essay that you are writing. Even if you have an idea about something, switch it up a little and add your own essence.