To take at least one night of sleep before a big decision is a very good idea.

You should adjust the decision time relative to the size of the long-term output of it. Therefore, if a decision can affect positively or negatively over a span of 10 or 20 years, or even your whole life, in a very high degree, perhaps even a month of thinking about it is not excessive.

If the decision would affect you over the next year, then you might take one or a few days to think about it. The advantage is usually you can find this amount of proportional time to think about it.

If it’s an hour that’s affected, you can take 2-3 minutes to think about it specifically and even writing down your thought process.

Another area to think about is things you do repeatedly. Take them into account. Think if you are doing it right, or if there is something you might change that would improve the easiness, quality and/or quantity of it.

For example, a big part of your life is sleeping. Did you take the time to think closely on how you sleep? Whether you are doing it right, not to little and not too much. It is roughly a third of your life, therefore it deserves the time to think about it seriously.

Sketch out your thought process on paper. Visualizing and putting thoughts into written words helps a lot.