This is inspired by talking to my sister, because she stresses over decision-making and I’ve always been much more easy-going. There are a couple different parts of decision-making that I’m going to write about in this post.
If, after doing whatever research you deem appropriate, you’re choosing between several alternatives that seem roughly equally good–a common example would be choosing where to attend college, if you’re going to college–I think the right thing to do is just make a decision. If your choices seem similar, then they probably are similar, especially if you properly did your research. Make a decision and things will be fine, is my experience.
Related to this is how you should evaluate decision-making. An important thing is that in evaluating decision-making you must not use any results from the decision when evaluating it. When you’re making a choice, you have limited information. Sometimes, the information you have might lead to a bad result, but that does not necessarily mean your choice was poor. Sports provide lots of easy examples of this. Clayton Kershaw is the best pitcher in baseball and choosing to start Kershaw in game 1 of a playoff series is clearly the correct decision. Sometimes you get game 1 of the 2014 NLDS, where Kershaw got hammered. Given what you knew at the time–that Kershaw is the best starting pitcher in baseball–starting him was still clearly the correct decision.
From a sports follower’s perspective, the way that sports writers use results-based “analysis” of various decisions is immensely frustrating. How well Sam Bradford actually plays this season should not change your evaluation of the Vikings’ trade for Bradford at all. You judge the trade based on what you knew at the time it was made, so you weigh how well you expect Bradford to play and the cost (including cap hit) of his salary against the expected net value of the draft picks the Vikings gave up.
The right way to use the results of a decision to inform future decisions is to use them to figure out if your decision-making process is flawed. Sometimes the best information you have still leads to bad results, and you will do better in the future if you accept this. Improve the information, if you can.