When defining Vue components with TypeScript, use appropriate component definition patterns to ensure proper type inference and avoid breaking type changes. For proper typing of component props: 1. Use the correct helper for your component definition needs. For example, `DeclareComponent` may be more appropriate than `defineComponent` when you need to expose prop types in a specific way. 2. When providing default values for function props, remember they're handled differently than object/array defaults: ```ts // Correct way to define function props with defaults props: { handler: { type: Function, // Function props don't need to be wrapped in factory functions default() { return (value) => console.log(value) } }, // While object defaults need factory functions objProp: { type: Object, default: () => ({ key: 'value' }) } } ``` 3. Be cautious when modifying type definitions or signatures of public APIs, as these can introduce breaking changes for consumers. Maintain the expected type argument order for exported types like `DefineComponent`. By following these practices, you'll ensure your Vue components have proper TypeScript support while maintaining compatibility with Vue's type system.