Some of her tips (and I highly recommend you read her blog in detail):
1. Authenticity before marketing. Have personality. Build community.
2. Be nice. Be thankful. Reply and Retweet!
3. Don’t tweet about your coffee (unless it is fair trade), the weather, or how tired you are.
4. Don’t only Tweet your own content.
5. Limit your Tweets to 5 per day, and no more than 6!
6. Create an account on Bit.ly and track your Twitter referral URLs.
7. Poll your followers to increase participation. Use twitpoll.com.
8. Register your organization’s Twitter account with TweetMeme. TweetMeme is like Digg, but with Tweets.
9. Use Lists to build relationships with donors, volunteers, partner organizations, etc.