According to Jim Pryor of New York University, philosophical writing is different from the writing you will be asked to do in other courses. Professor Pryor has created a helpful online guide which includes:
What Does One Do in a Philosophy Paper?
Three Stages of Writing
Early Stages
Write a Draft
Rewrite, and Keep Rewriting
Minor Points
How You'll Be Graded
His very helpful guide can be found at: http:/./www.jimpryor.net/teaching/guidelines/writing.html