Your reader is giving you what is most precious: time. Be respectful. Be concise.
Concise writing is powerful. Compare "he strode in the room, chest out, head high" with "he walked into the room with an air of confidence, soldier-like, marching with his chest out and holding his head high."
When possible, even when writing academic research papers, try to avoid disclaimers and qualifiers. Words such as "might" and "probably" are often not necessary. Statements such as "It seems as though" or "it might be the case that" add verbiage and erode the reader's confidence in your authority. Be bold. You are the authority on your subject. That is why you are writing about it and people are reading your work.
Avoid redundant clauses and phrases. When we repeat ourselves, the reason is often because what we are not certain what we want to convey. The process of writing can clarify your thinking on a subject. Never be satisfied with your first draft, because writing that first draft may have clarified what you think about a subject or how you imagine a character or scene.
Use adverbs sparingly. Often, adverbs are redundant. She should not enter a dimly lit room. She should enter a dim room. Is there a different adjective or verb available that conveys your thought than the adjective that you want to modify with an adverb? Why would she run quickly if she can sprint?
Your style and voice will emerge from your choice of words not the quantity of your words. You will not impress your reader with your ability to string many clauses together into a sentence. You are likely to bore your reader instead. You will impress your reader by using the best word in the English language to convey what you mean. Be precise in your vocabulary. Nothing produces elegance like precision. A well-fitted suit or dress, cut to the contour of the wearer, is elegant. Ill-fitted rags are not. Cut your language to the contour of your meaning; do not drape your subject with tatters.