Use short, familiar words. Vocabulary is a tool, a means to an end. It is not an end in itself. While a large vocabulary is a great asset, use it graciously. Don’t show off with it. Don’t use large words when a small one will do. Small words will make your writing clearer, more precise, and more beautiful.
Keep sentences short and simple. Your sentences should average less than 20 words. Better to express a thought in several short sentences than in one long one. Your writing will be easier to write and to read. And you will be stuck less often. Don’t worry about it sounding choppy. Writers are much more aware of so-called choppiness than readers are.
Prefer active voice verbs; avoid passives. Nothing adds more dullness to writing than the passive voice. Worse, it makes your writing inaccurate because it fails to tell by whom. Passive voice is easy to identify because it always begins with a form of the verb “to be.” Guard against using verbs that begin with “is,” “was,” “has been,” etc. Write “The professor smashed the glass” instead of “The glass was smashed by the professor.”
Get people into your sentences. Impersonal writing is hard to justify and makes for dull reading. Write, “We decided” instead of “It was decided.” Your writing will be easier, and yes, you may call yourself “I.”
Use a conversational style. Write it the way you would speak it. When you’re struggling over a tough passage, ask yourself, “How would I say this to my friend at dinner, or to the reader if he and I were discussing this at lunch over a soda?” But caution: you must be far more careful to be accurate in writing than in talking.
Gather all your information before you start writing. Vague generalities are caused by unsure writers. The best way to be an expert writer is to be an expert on the subject you’re writing about. Your assurance and self-confidence will show through your writing. But say only what you have to. Don’t try to tell everything you know about your subject.