Start small and build over time. Begin by auditing your current UI—gather buttons, headers, forms, and spot inconsistencies. Then, define your core styles: color palette, typography scale, and spacing system.

Create your first reusable components like buttons, inputs, or cards based on those styles. Document them clearly in a shared space (like a Figma library or internal style guide).

As you design new features, add and refine components. A good design system grows iteratively with real product needs—consistency, collaboration, and team feedback are key to success.