How you go about making a decision can involve as many choices as the decision itself. Sometimes you have to take charge and decide what to do on your own. Other times it's better to make a decision using group consensus. How do you decide which approach to use?
Making good decisions is one of the main leadership tasks. Part of doing this is determining the most efficient and effective means of reaching the decision.
You don't want to make autocratic decisions when team acceptance is crucial for a successful outcome. Nor do you want be involving your team in every decision you make, because that is an ineffective use of time and resources. What this means is you have to adapt your leadership style to the situation and decision you are facing. Autocratic styles work some of the time, highly participative styles work at other times, and various combinations of the two work best in the times in between.
The Vroom-Yetton-Jago Decision Model provides a useful framework for identifying the best leadership style to adopt for the situation you're in.