Most designers learn UX principles for job interviews and then forget them the week after. That's a waste, because these things are genuinely useful and have been developed because it has mattered. When someone asks why you made a particular call, a named principle is the fastest path to an answer that actually lands. Just saying 'Occam's Razor' won't cut it, that term is for you, the designer. You have to use the term as evidence in your argument as these principles are the result of studies. Suddenly you're not defending your taste or arguing about who is right and instead using documented human behaviour as leverage to create a better product.

I've discussed some of these points before just as points but here are some in context I have used in discussions and healthy arguments with product managers and engineers:

1. 1. Take Jakob's Law. Users spend most of their time on products other than yours, so they arrive with mental models already formed and expectations already locked in. They expect a form to submit when they press Enter. They expect a checkout flow that resembles every checkout flow they've used before. Jakob's Law is exactly why you think twice before reinventing a navigation pattern that every major app already shares. The familiar is faster and allows headroom for innovation elsewhere that matters.
2. 2. Occam's Razor, applied to design, becomes a constant pressure to cut things. Given two solutions that both work, the simpler one wins. A search bar beats twelve filter options. One clear call to action beats three competing ones. Simplicity is a bet that fewer moving parts serve people better.
3. 3. Hick's Law tends to surprise people who haven't encountered it: decision time increases with the number of choices, and not in a neat linear way. It compounds. Four or five items in a tab bar outperforms eight, consistently. "Sign up with Google or Apple" converts better than a grid showing every OAuth provider you technically support. More options feel like generosity from where the designer sits. From where the user sits, each extra option is a small tax on their attention which adds up.

The reason these principles are useful in real debates is that they describe actual human behaviour, not designer intuition. They give you something to point to when a stakeholder wants to add three more items to a dropdown "just in case." Rather than arguing from gut feeling, you have a named, tested pattern that backs the decision.

Used well, these principles employ shared vocabulary for getting to a good decision faster. The designer who reaches for the right principle at the right moment is a true advocate for the user.