Please Note: These are only common assumptions and suggestions about writing an outline. The requirements of such assignments often vary, so please follow your instructor's guidelines.
An outline is a tiered, visual representation of your plan for ideas in an essay. To be best prepared for writing your outline, it is recommended you first brainstorm ideas that could eventually be included in your essay. Using your assignment requirements, you can then cut out ideas that will not work and discover areas that need more brainstorming or research for development. Once all that is done, an outline will be much easier to make since you will have potential ideas already listed out that you can arrange and rearrange to fit wherever they work in the outline best.
For more specific information about how to arrange, design, and create an outline, please see the linked handout: