Wow, it have been a while. I had to read this again :)

Check this great article from 2003 about

writing good user stories:

  • I – Independent
  • N – Negotiable
  • V – Valuable
  • E – Estimable
  • S – Small
  • T – Testable

and great tasks:

  • S – Specific
  • M – Measurable
  • A – Achievable
  • R – Relevant
  • T – Time-boxed