You need some kind of a plan, especially if you are an inexperienced writer or if you are writing anything longer than a few hundred words. The type of plan you write will depend on the type of text you are going to write and its length. So a plan could be anything from a few ideas in your head for a brief note to a detailed written outline for a long essay or report. If you are writing anything longer than two thousand words, it would be difficult to write a well organised coherent text without a detailed plan or outline.
The animation below shows what a basic plan should contain and how it can help you to organise your writing.