What makes a decision a good decision?
You Must Decide
At the time we decide something we can only do it with the information we have at that time. It is easy to look back and regret decisions. The reality is that at the time of the decision we didn't know all the details that we do when we look back at a decision.
We need to speculate when we are about to take a decision, try to understand the future, what will happen when... what will happen if...
The best we can do is to decide based on the information we have at the time and we should never regret that decision, maybe feel a bit sorry. :)
For me the worst decision is the one that is not made, the ones that takes ages to make. Taking a decision requires courage, and I'm sure you know people around you that tries everything to not have to make one. At the end of the day not making a decision is the decision you made and you should still be accounted for that.
So, to try to save yourself for making a wrong decision do one thing: DECIDE