I'm entering some text here primarily so there will be some sort of user page. Like others, my interests vary greatly. My job involves a great deal of writing so grammar, style, and usage interest me (believe it or not). My other interests include law, open-source software, (more technically, free software), rhetoric, philosophy, liberalism, and the game of Go.
Some writing principles I try to follow, many of which overlap, and all of which have exceptions:
1. Prefer active voice over passive voice. Sometimes, though, the passive voice is better.
2. Economize words. Don't say in 50 words what you can say in 10.
3. Write to communicate; not to show off. Don't use big words or long sentences to show you're smart. You will not sound smart. You will sound like someone trying to sound smart.
4. Make your writing speakable.
5. Don't be afraid to begin a sentence with "and" or "but." Elementary school teachers perpetuate a myth to the contrary, probably to help students form complete sentences. That said, don't overdo it.
6. When you see the word "of," try to remove it. This is more of a trick to spotting the passive voice than an independent principle.
Know the differences between:
"that" and "which" ("which" is NOT a more formal "that");
"your" and "you're"
"their," "there," and "they're"
"its" and "it's"