I definitely need to work on this in my writing. Back in 2005 when I was still a musician and writing songs, there was this "poetry" Web-site, which had a search engine for many kinds of relevant word queries by meaning or tone of the words, but I can't recall the name of the site. It really made it easy to accidentally discover very cool words, which I wouldn't had recalled on the spot during writing the lyrics.
So what I would like to find is writing excercises and methods you could use to spice up your word choices.
