Here's a quite-difficult writing exercise I recently gave to my students:
Using one-syllable words ONLY, write a short scene from a story (or you could even write a long-ish poem or mini-essay).
Students surprise me every time with this assignment. Because of the difficulty level, I'm usually expecting them to come up with a somewhat simplistic, nursery-rhyme-ish, sing-songy-sounding story/poem. But they don't. Their work is poignant, rich, deep, philosophical, and oftentimes, funny!
It's one of my favorite in-class exercises - not only because it's challenging, but also because of what it teaches the students. Every time, without fail, the students tell me something along these lines: "This assignment made me look at every single word SO closely. I really had to slow down and think about my word choice."
What a great lesson for all writers - the importance of word choice. How about these: hurt vs. ached; exciting vs. scintillating; loud vs. sonorous. We writers have total control over what ends up on the page - word choice is our choice. And it's not that the words have to be formal-sounding or overly-descriptive or intellectual-sounding. But one word can create one image in the reader's mind, while another word can create an entirely different image. It's that important.
For me, keen attention to word choice happens in the editing process. The rough draft is for pouring my thoughts/ideas on paper nearly the moment they spill out. But in the editing process, I slow down, almost painfully-so, and pay careful attention to sentences, to individual words. And yes, I break out my thesaurus from time-to-time. No harm in that! It's one of a writer's many tools.
So, today, why not give this one-syllable exercise a try? (I'd love to see a few of them posted in the comments! How fun! I'll start...*takes a breath and dives in* lol).