Great advice here from Brendan Baker - love the breakdown on buckets. A very practical way to assess your milestones and craft your story.
http://brendanbaker.tumblr.com/post/16830178199/derisking-buckets-how-to-identify-and-deal-with
http://brendanbaker.tumblr.com/post/16830178199/derisking-buckets-how-to-identify-and-deal-with