✅Inspect the basin and identify the blockage cause (slow drainage, standing water). ✅Clear debris using a plunger or a drain snake to dislodge the blockage. ✅Remove and clean the U-bend trap under the basin if needed. ✅Flush the drain with hot water or baking soda and vinegar to clear residue. ✅Reassemble all components and test the drainage to ensure the flow is restored. ✅Clean up the work area and check for leaks after completion.