I’ve read varying opinions on the use of a thesaurus when word-painting. Some writers will tell you not to even go there. Others swear by this reference book as an adjunct to their writing experience. I think the bottom line is–choose words that flow within the context of your narrative. If a word sounds stilted, if it forces the average reader (based on your intended audience) to run for a dictionary, if it’s out-of-character to the speaker or your narrative, then I say, forget it.
I do like to consult the thesaurus and from time to time will go to Rodale’s “The Synonym Finder” or Kipfer’s “Flip Dictionary.” That may be a function of the aging process, I’ll admit, when that word is just hankering to jump out of your brain but you can’t catch it.
Back to the litmus test for word choice. How does it sound? Does it fit into your style and is it suitable for your intended audience?
Much, much better to go with something simple and unnoticed than a word that screams “Look at me reader! Ain’t I something?”