... and never begin to add detail too early.
Start the process with blocking out the entire animation (perhaps using stepped tangents). Just in case there's a director or animation supervisor it would be a waste of time to do detailed stuff which you have to do again because the overall action isn't accepted.
In addition, check out this dvd:
Maya Techniques | Fast Animation Rigs, by Jason Schleifer (Senior Animator and Creature Technical Director at Weta Digital)
(Alias Learning DVD)