The University of Waterloo (link) offers a number of approaches to effective decision-making. Here is a summary of a few suggestions:
Finding Consensus
The University of Waterloo offers different approaches to come to a consensus. This one might be more time-consuming, but it is a good way to reach an overall agreement.
The decision is discussed and negotiated until everyone affected by it understands and agrees with what will be done. Consensus in decision making means that all members genuinely agree that the decision is acceptable. After a group has identified a decision to be made, each member is asked how he/she feels about the proposed decision by selecting one of the following responses:
If all the responses from the group members are 1, 2, 3, or 4, you have a consensus and are ready to move on.
This is the best way to make decisions, if you have the time, so that all members feel that they have had an equal opportunity to influence the decision and will continue to support the group.