Minus an "E": Inspired by Ernest Vincent Wright's Gadsby: A Story of Over 50,000 Words Without Using the Letter "E" in this exercise I challenge you to write for 15 minutes and the only limitation is you cannot use the letter "E." For variations on this assignment, choose a different vowel (no fair choosing "Y") and write for 15 minutes without that vowel instead.
The idea here is that by limiting which vowels you can use, you have to stop and really think about each word you choose. It exercises your brain in a way that regular writing doesn't. Sure, you might not produce a work of genius with this exercise, but it trains you to think about word choice and you'll start seeing the results in your writing in general.
Single Syllables: Another exercise I learned from a favorite writing teacher is to write for 15 minutes using only one-syllable words. Not only does it make you stop and choose your words carefully, but by using only one-syllable words you'll infuse your work with energy and punch that you don't get from words with multiple syllables.
Sometimes when I feel like a piece I'm writing needs more punch, I'll go back and rewrite a section, trying to use more one-syllable words. The change in the energy never fails to amaze me.
What do you think? Do you think you need to set some limits in your writing? If so, what tricks have you used that work?