Marco details his best practices for using RSS:
If a site posts many items each day and you barely read any of them, delete that feed. If you find yourself hitting “Mark all as read” more than a couple of times for any feed, delete that feed. You won’t miss anything important. If they ever post anything great, enough people will link to it from elsewhere that you’ll still see it.
Yup, and you can apply the same rules to your Twitter feed.