A plan will help you organise your ideas. Ideas can be single words, you don’t have to write complete sentences. When you have enough ideas organise them into paragraphs. Think about how many paragraphs you are going to write and organise your ideas into the paragraphs. Many pieces of writing need four clear paragraphs. For example:
Paragraph 1 - The background to the story, characters and setting
Paragraph 2 - A problem – what happens to the main character
Paragraph 3 - Solving the problem – events that happen with lots of suspense ... will the problem be solved?
Paragraph 4 - The ending. This might be funny, scary or strange
A for and against essay
Paragraph 1 - Introduction – what the essay is about
Paragraph 2 - Ideas and arguments in favour
Paragraph 3 - Ideas and arguments against
Paragraph 4 - A conclusion with your opinions
To practise your writing have a look at the Writing skills practice section.
When you have a clear plan it is much easier to write well so it is worth taking time at the very beginning of the exam to think and plan.
Do you ever write a plan before you start a writing exam?