When an editor asks you for a more sophisticated tone, simply using more ten- and fifteen-cents words instead of perfectly good five-cent words will not achieve this for you. “Utilise” instead of “use,” “perceive” instead of “see,” and “ponder” instead of “think about” merely clutters up the prose for the reader. Get to the point. A thesaurus is a useful tool for a writer at times, yes; however, your reader shouldn’t have to use one to get through your book. Sophistication arises from how you approach the subject, not the words you use to discuss it.