Plan your answer
Think about a wedding. If it wasn’t planned properly, then the bride and the groom would turn up at different churches, the priest would have taken the day off in any case, and there’d tears before bedtime.
The same thing applies to any essay work you have to write in an exam. Fail to plan and you plan to fail.
Brainstorm your ideas, mark each idea with the paragraph number they go in, and only then should you go about writing the essay. Make sure your plan is on the exam paper, where the examiner can see it. As a math’s teacher might say, “Always show your workings.”