Write with a position or point of view in mind. For students past the sophomore level, papers should go beyond description. Description may be used to persuade, but should not be the objective of the paper. A good paper should take a position, make a point, persuade or convince the reader that a particular approach or point of view is correct. A good paper probably does not need a conclusion because if the paper is well written, the conclusion should be clear to the reader.
Short papers develop incisive writing.
Long papers often ramble. Require a short paper. The introduction is a key source of procrastination and should be written last. Ideas evolve with writing. Writing is a thinking tool.