There are two kinds of travelers: the ones who build spreadsheets and color-code their packing cubes — and the ones who wake up at noon and ask, “Where should I go today?”

Most people fall somewhere in between. The truth is, whether you should plan ahead or wing it depends less on your personality and more on where you’re going, when, and how you travel.
Here’s how to find your sweet spot — one that saves you money and leaves space for a little serendipity.