I’ve been asked by a number of people how to become a better writer. Despite my current publications, I still find myself more in need of advice than I am prepared to offer it, but I do try to help. I don’t know where I first heard it, but what I usually pass on, and largely all I’m able to pass on is the one thing that worked for me, the “ass-on-chair” approach. (Proofreading comment: Also, avoid long, complex sentences such as the preceding one like the plague. And avoid cliches too! Don’t touch them with a ten foot pole!)
For some better and more detailed rules on how to learn to write, see 10 Steps to Becoming a Better Writer.