Pre writing is exactly what it sounds like: Pre Writing; that is, before writing. Prewriting is just coming up with lots of ideas about a topic before beginning the drafting process. For some, it is actually harder than the actual writing part because it requires the writer to start from a blank page. IPrewriting is also often called brainstorming. 
Freewriting is one method of brainstorming.  In this method, the student starts off with a topic. It can be as focused as: “Describe your main character” to as vague as “What do you want to write about?” In freewriting, students just writes\ everything that comes into their head. They don’t correct grammar, punctuation or spelling. They don’t worry if the ideas are good or not. They just write down everything, even if it’s “this is stupid, I can’t do this, I can’t think of anything…” It’s generally a good idea to freewrite for at least ten minutes at a time. When finished, the student can look over the freewriting to see what ideas are usable.
If students are comparing and contrasting several articles, people, places, etc., they may consider using a Venn diagram. To create this diagram, consider the similarities and differences of the material being analyzed. Place ideas in circles that overlap. The similarities should be placed in the overlapping portion of the diagram.

Venn diagram

Clustering is another method of brainstorming, combined with organizing. Some people refer to this method as “webbing.” Students begin with the topic in a circle in the middle of their page. Students draw lines away from this circle and create other circles. For example, they may start with “writing” in the main circle. Because writing is a broad topic, it may need to be more specific. So students may draw one line and draw a circle with the word “newspaper.” Another line may end with a circle and that word “fiction.” There may also be circles for “magazine” and “nonfiction.” All of these are types of writing. From there, students may decide to be more specific about newspaper writing, so they may write the following (in separate circles off of “newspaper”): editorial, sports, business, entertainment, news, etc.

In order to create an outline, students will need a thesis statement. (Consider audience and the purpose of this paper.) An outline may look similar to the following, depending on the assignment, length requirements, etc.
Listing is another form of prewriting. Like freewriting, all ideas are acceptable. Students write down many things to help develop ideas, and no idea should be censored. Some students like listing better than webbing or freewriting because it is neater. Creating a list is also useful for developing characteristics of something. It can be used for description of setting, physical and emotional characteristics, and to help students think of similarities between ideas.