Decision-Making Pitfall 2: Escalation of Commitment: Committing further resources to what eventually proved to be a failing course of action. How to avoid:

Set limits (Determine what criteria and performance standards will be necessary)
Avoid the bystander effect (Avoid to do nothing out of fear of acting foolishly)
Avoid tunnel vision (Get several perspectives on the problem)
Recognize sunk costs (Money and/or other commitments previously spent cannot be recovered)
External review (In some cases, remove  or replace the original decision makers from deliberations)

Decision-Making Pitfall 3: The Abilene Paradox: A form of pluralistic ignorance; team members adopt a position because other members desire it, team members don't challenge one another because they want to avoid conflict. How to avoid:

Decision-Making Pitfall 4: Group Polarization: The tendency for group discussion to intensify group opinion, producing more extreme judgment than might be obtained by pooling individuals’ views separately.
Group Polarization is not simply a case of social compliance; people really believe the group’s decision.

Resource:
Book: Making the Team, a guide for managers (by Leigh Thompson)