Democracy works well, with some drawbacks, as a governing strategy. In most task-oriented groups, however, the most successful groups will have a clear leader, perhaps a leader who is closer to a benign dictator than a consensus seeker.
With a leader who has the position because he or she is knowledgeable and skilled--and not necessarily the most senior person present--the next most useful step is for the leader to convince the group that success or failure will be attributable to the group, not an individual. This may seem like a given, but it is a very important concept for the group to believe, not just hear. The leader may use the tired, but useful, analogy of cogs in a wheel--the group is the wheel, the individuals are the cogs--if one or two cogs break, the wheel stops. Groups who succeed internalize the concept that functions, not names or titles, make groups work.
Most individuals within groups function most effectively when given specific responsibilities. For example, the group's leader may set out the overall goals of the group very precisely--a group must understand exactly what it is required to accomplish in very specific terms. Another member should be given the task of keeping the group focused on the overall goal so that individual do not waste time on tangential efforts. The group's leader should be the person who monitors the activities of the group to insure that individual activities or discussions are directly related to the group's overall goal. Another member, never the leader, should be given the task of becoming spokesperson for the group, which requires that person to integrate the individual efforts of the group's members. The most detail-oriented person should be given the task of setting a schedule for goals to be met and monitoring the tasks as the group works. Every member must clearly understand his or her role in the overall effort and that effort should be within that person's skill set.
Because a group will almost certainly consist of individuals of varying strengths and weaknesses, the leader should attempt to pair weak and strong individuals. This may seem counter intuitive, but in most group situations, a weak individual will usually try to match a stronger person--in other words, a weak player becomes stronger by imitating a stronger player. If the leader tells the group that he or she believes the group will be successful, each member of the group will at least try to add to the ultimate success. And if there is a group member who is clearly obstructive, the leader can intervene and have a private motivational discussion with that member. If two group members appear to be consistently at odds with each other, the leader should tell them to leave the group, remind them that they are adults, and tell them to return with their dispute settled.
With group efforts, probably the most important belief for the leader to instill is that the group clearly has the capacity to succeed and that success is the expectation not because success is necessary but that success is a foregone conclusion given the make-up of the group.