Use shorter words unless there is a need for precision. Shorter words help quicken comprehension. When to break that rule? Avoiding repetition, adding rhythm and where the is a real distinction between the choice of two words.
A good journalist will use the fewest words possible to convey a thought.
A useful maxim: Any word that can go, must go.
Within a piece of work, the same point is made. Reduction is required.
Making simple points sound more complex than they are. Simplify as much as possible.