Shortening sentences is one of the easiest ways to change your writing style. Deciding to cut words, remove unnecessary qualifications or simply breaking a long sentence into two or three shorter sentences dramatically alters your writing style.
The recommended average sentence length is between 15 to 18 words for a clear and easy reading style. You'll need to shorten it if you're writing advertising copy and you can lengthen it slightly in a business report. However, the higher your sentence average goes above 20, the less readable your writing style becomes.