Regardless of the type of assignment, good writing has several common elements, shown below in order of importance.

Common Elements of Good Writing (adapted from Greenlaw (2005) Chapter 5)

• Focus - The paper should have a clear point, expressed as a thesis sentence, early in the paper.
  
• Organization - The purpose of the paper is to prove its point. To that end, the paper should be organized as a series of major sub-points which lead logically to the thesis as the conclusion.
  
• Solid Development - Each of sub-points should be explained in sufficient detail to convince the reader of their validity.
  
• Clarity, Concision, Precision - Say what you mean, as clearly and concisely as possible. Vagueness or ambiguity suggests to the reader that you're not sure what you're writing about.
  
• Grammatical Correctness/Avoidance of Spelling & Typographical Errors - Grammar is a convention to improve communication. Grammatical mistakes or typos convey that you either don't know how to write correctly or you don't care. Which of those conclusions would you prefer the reader to be left with?