This question is similar to this one (How to efficiently make a hard decision?) except I'm concerned more about improving the speed and effort taken to reach a decision.
So just come off organising my wedding and subsequent honeymoon. I noticed the prep was very stressful, but the stress wasn't just over all we had to do, it was the decision making over some fairly big purchases. Booking a reception or flights - basically things that would cost a lot of money and lock us into a particular path, it would take ages for us to decide anything. We'd try to do as much research as we can (often making us even more unsure cause there was so many options) and then even after that, and we'd worry about whether we made the right decision.
Maybe we're just indecisive, but making decisions takes a lot of mental effort!
What strategies is there to enable someone to make important decisions quickly and without applying so much effort?