You should always make sure that you are using strong adjectives and verbs. Always make sure that you avoid using articles and simple pronouns excessively, and eliminating contractions (words such as "can't, don't, won't). Break the words up into their full form such as: cannot, do not, will not). Make sure that you are altering your word choice in accordance to the importance of the essay. A good rule of thumb is to refrain from using words that you would often use in a text message. For example, if you are inquiring about a job position, you should not use the same context you would as a friend or close relative. When you are evaluating a piece of writing for word choice, another good tip is to read the piece aloud. Doing this allows you to hear how the potential reader will read it. If you read your piece and it sounds as if you are talking with friends, then you should alter the word choice. Make sure that simple adjectives such as good, fine, or happy are replaced with more detailed/strong terms such as "proficient", "excellent", or "exuberant". These words are much more descriptive, and provide the reader with more context. I hope this helps.