Question: If there is only ONE thing you can pick up from Agile practice, which one do you want to choose?

Answer: Retrospective.

Retrospective is not only a learning process - to discover, share, and pass along from past experience, but also for the improvement, a best way to grow project by project. In addition to that, retrospective is an efficient and important way for team building - yield foster a stronger and better team.

As Retrospective Prime Directive, in Norm Kerth's book <<Project Retrospectives: A Handbook for Team Reviews>> points out - Regardless of what we discover, we understand and truly believe that everyone did the best job they could, given what they knew at the time, their skills and abilities, the resources available, and the situation at hand.

As in another good book <<Agile Retrospectives: Making Good Teams Great>> says: 

"With regular tune-ups, your team will hum like a precise, world-class orchestra."

A true Agile practice really makes sense in the end ...