I’ve heard it said that good writers don’t need a thesaurus. On the contrary a good writer knows s/he needs a thesaurus. That’s why s/he is a good writer. A good writer also needs a good dictionary and uses it periodically throughout the writing session. I have three immediately accessible from my writing space – I keep a large volume Macquarie’s Dictionary, a concise Macquarie’s Dictionary and Encarta Dictionary tool to compare spellings and definitions. I also have The Writer’s Digest Flip Dictionary (FD) which uses of combination of dictionary and thesaurus entries, but it is neither a true dictionary nor a true thesaurus. The FD works in reverse from true dictionaries in that the user searches using cue or clue words based on concepts or definitions. Following hierarchies the FD catalogues precise words and alternatives for each concept or idea.
Any dictionary or thesaurus is an essential tool for writers, but don’t use them to perform ostentatious affectation of your lexicon – prolixty in literature is a sign of incompetence – as I have demonstrated here. Sometimes the most familiar words are the best choice. The point is to get the message across eloquently without being wordy or pretentious – a skill you can’t learn from a dictionary.