Avoid generalizations and non-specific language.
Be as precise and concrete as possible in all your statements.
Choose concrete verbs and adjectives over abstract ones. For example, “to use” is a non-specific verb that often appears in wordy, unfocussed sentences. What do you really want to say? What exactly is the character/author doing?
Weak: Shakespeare uses Nerissa as Portia’s sounding board.
Better: Nerissa functions as Portia’s sounding board.
Best: Nerissa’s plot function as sounding board allows Shakespeare to convey essential information to the audience.