Every day you are faced with making decisions. You don't always have all the information, and a big part of deciding optimally refers to the trade-off between spending time gathering information and making the decision.
Since deciding optimally means you have to make decisions without all the information, how can you possible know that you have enough? You might initially think that the amount of data you need depends on how important the decision is. But what if the best option is clear? This suggests that what we really care about is the range of possible outcomes.
Rather than detailing all the things you might consider, I'll describe a possible decision-making process. Say you move to a new town and want to pick out a gym. The list of available options is sitting in your phone book. But are all of those actually options? I like swimming, so any gym I choose will need to have a pool. Based on my experience, a lot of gyms have pools, so I would probably eliminate any far away gyms first, and then find out which of those left have pools. Lastly, I would want to rule out any terrible options by looking up reviews. At this point, any of the options I have left meets all my needs, so the difference between the worst and the best is not so large. I could still spend all week trying to make a decision, or I could just pick a criteria, and go with it. In my case I would just go with whichever option is cheapest, but you could pick the cleverest name or the prettiest website too. Without too much time, I've made a decision that should be, approximately, the best.
In short, to decide optimally you should consider your options, eliminate options based on your priorities until all remaining possibilities seem to be approximately the same goodness, and then pick any easy to know criteria to choose based on. This won't ensure you always make the best decisions, but it does give you a choice you can stand behind.
