Tokens first
Colour, spacing, radius and type scale defined once and referenced everywhere is 80% of the value of a design system, and it takes a day.
Primitives, then patterns
Buttons, inputs, cards and layout containers cover most screens. Build patterns only after the same composition appears three times.
Keep design and code in one language
When the Figma library and the component library share names, handover conversations get shorter and drift becomes obvious.