Good UX rarely happens by accident. A lot of what feels "intuitive" is just designers quietly applying principles from cognitive psychology that have held up for decades. You don't need all of them - but a few are worth keeping in the back of your head, because they explain why something "feels off" when you can't put your finger on it.
Hick's Law
More choices = slower decisions. So simplify navigation, cut form fields, one clear CTA per page. Decision fatigue is real, and every extra option you add is a small tax on the user.
Fitts's Law
The time to hit a target depends on its size and distance. Translation: make buttons big enough and put them where people already are. On mobile, tap targets should be at least ~44px. Tiny buttons aren't minimalist, they're just annoying.
Miller's Law
People hold roughly 7 (give or take) items in working memory. So chunk information into groups and reveal things progressively instead of dumping everything at once.
Jakob's Law
People spend most of their time on other sites, so they expect yours to work like the ones they already know. This is the one designers fight the most - don't reinvent navigation, forms, or checkout just to be original. Familiar beats clever.
The Peak-End Rule
People judge an experience by its most intense moment and its ending, not the average. So build a few genuine delight moments, and don't neglect the ending - a thoughtful confirmation or thank-you screen is the last taste people leave with.
The Law of Proximity
Things placed near each other read as related. Group related fields, put labels right above their inputs, keep a CTA next to the value it's promising. Spacing is communication.
Keeping them in your head
You won't consciously apply all six every time. But next time a screen "feels wrong" and you can't say why, run down this list - the culprit is usually right there.