The blog, Dumb Little Man! publishes tips weekly “that will save you money, increase your productivity, or simply keep you sane.” I particularly like the keeping me sane part.
He’s got all sorts of tips; the blog is worth taking a look at.
Not too long ago he posted 50 Tools that can Improve your Writing Skills. Each is a link to a resource that’s truly helpful – mostly, maybe even all, from Poynter Online. I’m still working my way through them all.
So far my favorite is Writing Tool #2: Use Strong Verbs.
One could do worse than take one tip a week and work on it; by the end I suspect your writing (and mine) would be much better.