sleep on it

This is on the list of Harvard Business Review Breakthrough ideas of 2007:

Conscious deliberation, however long and careful, can be a surprisingly crude and ineffective tool.

Use your conscious mind to acquire all the information you need for making a decision—but don’t try to analyze the information. Instead, go on holiday while your unconscious mind digests it for a day or two. Whatever your intuition then tells you is almost certainly going to be the best choice.