Each time someone asks me to teach them how to make better decisions, I start with the same fundamental principle Professor Ron Howard teaches in his decision analysis course at Stanford:
Every decision has three parts: options, objectives, and information.
Like a three legged stool, if you take any of the three away, the decision topples.
Without options (plural), you are simply following a predetermined course of action.
Without understanding your objectives, i.e. what you prefer in the outcome, it's impossible to judge what option is better than the others.
Without information on how options and objectives intersect, you are blindly rolling dice.
Good decisions require consideration of all three parts.