Do not use sexist or biased language. For example, Mankind should be avoided in favor of the more general Humanity. More active and hence better verb choices are always out there begging to be used. The tests were graded by Dr. Hicks in a rather dilatory manner. Dr. Hicks graded the tests rather slowly.
Tone represents the writer's attitude toward the subject matter and the reader.
The writer's tone should not change toward either. When reading early drafts of essays, the following considerations should inform the reading and revising process. Continue revising essays until you can say 'yes' to each of the following questions. Reading your work aloud will help reveal areas where your writing may be stilted or awkward. Coming back to an essay after an interval will make errors easier to spot and logical flaws more apparent.