Proofing & Editing
Before submitting your work, ensure you proofread and edit well. This includes such tasks as:
Checking that words are spelled correctly (and used correctly)
Verifying capitalization and punctuation
Reviewing grammar
Looking for areas where you have extra spaces between paragraphs and/or sentences
Double-checking formatting
Checking that all sources are on the reference list (and no sources are on the reference list that are not used in the paper)
Bonus Tip!
It may feel silly but printing your paper and reading it out loud will help you catch errors that you will not catch by reading/skimming your work quickly.
Work that is not well-edited or proofread comes across as hastily and sloppily written. This impacts your credibility as a writer, and your grade as a student!
Here are some tips on proofing and editing your own work:
Writing Tone, Language & Voice
Writing in a formal, academic tone is important for writing in the mature style expected of academic writers - especially starting at the graduate level. When writing for academic assignments, you need to stick to a formal, academic tone. You want to avoid writing in a way that is too casual or conversational. If it sounds more like an email or text you might send to a friend or colleague, you are not quite there.
Honor your voice in academic writing, not the voice of the robots (more here).
Here are some additional sources for learning more:
USC Libraries - Academic Writing
Guide to using appropriate language in writing from the Purdue OWL.
Part of academic writing is ensuring you use active voice, rather than passive voice. More here.