Principles of great design

Key Takeaways

• Design = making something with intention, focused on what matters most to people

• 8 principles: Purpose, Agency, Responsibility, Familiarity, Flexibility, Simplicity, Craft, Delight

Presenters

• Linda Dong, Design Evangelism

• Doug LeMoine, Design Evangelism

Purpose

• Before sketching or writing a line of code, ask whether what you’re making has a purpose

• Every feature asks for the user’s time, attention, and trust — don’t waste them

• Design through subtraction: choosing what to build is often deciding what to leave out

Agency

• People feel in control when you let them do things their own way

• An interface should never stand in the way of what someone is trying to do

  • Don’t guide someone down a pre-determined path — let them dive into your experience and explore at their own pace

• Offering choices is the best way to bring agency into your experience → people are far more engaged

• Offer forgiveness — people will make mistakes or wander down paths they didn’t mean to

  • Make it easy to undo any action (send, change, delete)

  • Double-check destructive actions with a confirmation

  • Interrupt only when someone is about to make a big mistake → avoid disaster

  • Forgiveness lets people feel capable and free to explore, knowing they can always recover

Responsibility

• Giving people freedom means also protecting their well-being — act in their best interest

• Start with privacy (privacy is a human right)

  • Anti-pattern: throwing permission prompts the second the app launches, long before the user knows what it does

  • Anti-pattern: asking for information without context for what it’s for

• Treat people and their private information with respect, just like in the real world

  • Wait for the right moment to ask for personal data

  • Only ask for what’s necessary, and be transparent about what the data is for

• For intelligence features, anticipate that a model might generate something unexpected or inaccurate

  • e.g. a recipe app suggesting an ingredient someone logged an allergy to → real-world harm

• Think realistically about what could go wrong and add safeguards (previews, confirmations, disclaimers)

  • Consider removing a feature entirely if the risks to safety outweigh its value

Familiarity

• Building on what people already know — lean on their real-world experience and conventions from other interfaces to make your design intuitive

• Use metaphor (used since the earliest interfaces to help people get familiar with software)

  • Too literal → people may not recognize what you’re trying to show

  • Too abstract → you risk your idea not getting across

  • A good metaphor draws on something people know and helps them predict what it will do

• Don’t reinvent established metaphors — using a trash can for anything but delete breaks people’s expectations

  • For common actions, use the metaphors people already know and make them do what’s expected

• Familiarity also comes from being consistent — it helps people predict what happens next

  • Things that look the same should behave the same

  • Keep actions in the same place across screens and devices (e.g. close a window from the top-left on Mac) → people don’t have to think, it speeds them up

Flexibility

• People use your design in ways as unique as they are → support all the different contexts they’re in

• Flex across hardware and contexts — the same task (e.g. listening to music) differs at home (speakers), on a run (AirPods + watch), or driving (hands-free)

  • Tailor to each platform’s strengths: iPhone → quick touch interactions, Mac → deep workflows and precise pointer control

• Flex for the person using it

  • Get curious: how old are they? what languages? pro or novice? do they rely on accessibility features?

  • You won’t solve for everyone on day one, but start making the experience more inclusive

• Personalize — when no single layout fits everyone, let people rearrange or hide controls to match their workflow

Simplicity

• Strip away the unnecessary so the core purpose of your design can shine

• Simple ≠ minimal — burying all functionality in one place looks minimal but isn’t simple

• Simple designs are frictionless and intuitive: people find what they need without effort

• Achieved by being concise and clear

• Concise interfaces use plain language and respect people’s time

  • Strip away jargon and speak naturally

  • Avoid redundancy and get straight to the point

  • Reduce the number of steps it takes to get things done

• Clear interfaces perfectly communicate what they do — use hierarchy (order, spacing, contrast) to guide people to what matters most

  • Answer people’s questions: what do I pay attention to? what can I interact with? how?

  • Every element should earn its place — cut anything that doesn’t clarify your point

Craft

• Attention to detail that tells people you really care about the experience

• Poor craft feels fragile — laggy buttons, jittery scrolling, misaligned icons, broken layout on rotation

• Ingredients of well-crafted design

  • Beautiful fonts that look great across devices

  • Thoughtful colors that adapt across light and dark

  • Clear graphics and iconography

  • Responsive animations that feel fluid and give immediate, natural feedback

• Getting to that quality takes time — craft comes from iteration, making every last piece work beautifully

• Maintain your design over time — great design has longevity, so keep evolving it as new features and hardware arrive

Delight

• Hard to define, but you recognize it instantly — delightful interfaces are satisfying, enriching, and create a real emotional connection

• Not confetti or flourishes tacked on at the end

• Starts when an experience feels human — identify the emotion you want people to feel (relaxed, confident, excited) and reinforce it through your design

• Delight is the sum of the consideration you put in — the natural result of getting all the other principles right