One of the keys to effective decision making is confidence.
Even if you have temporary convictions, act on them. If you doubt your decision while making it, trust in your leadership may erode and you should never allow that to happen.
Strong opinions signal confidence and provide others with the guidence they need. But resist the urge to cling to your decisions. Have the humility to realize that you might be wrong if better information comes along. And yes, be prepared to change your mind and correct your course if that happens.