- A stylistic avatar. The best feeds have an avatar (little profile picture) that someone has put some thought into and that reflect, in some simple way, the content of the feed. Less interesting feeds just have a bland picture of the author. To a certain extent you can judge a book by it's cover! Just by scanning through avatars, you can get an idea of what feeds might be worth following from how interesting the avatar is.
- Talk about universal truths rather than what you are doing. Do I care that you are currently at Starbucks on Main Street? Give me something I can use! Unless you intend your feed for only your five closest joined-at-the-hip buddies, no one really cares what you are doing.
- Personally, I believe your "what I'm doing" stuff should go on Facebook. Even then, you should limit your updates to things that are somehow useful to others.
Here is some information on my own Twitter feed including my tweet archives. My best tweets respect the rules above.