The most constructive criticism will come from other team members, because they are most familiar with each other's work. But proceed gently here: Some team members may feel uncomfortable evaluating their peers.
o To get started, try having everyone share his or her opinion of how effective the team has been and what it needs to do to improve.
o If there is a general consensus about these issues, move on to feedback about individual members—have each person begin with a self-assessment.
o Be prepared to handle conflict, anger, or hurt feelings when members start evaluating each other.