Selecting the material is the most critical decision for durability and aesthetics. For residential interior doors, MDF (Medium Density Fiberboard) with a PVC wrap or lacquer finish is cost-effective and provides a smooth surface. For high-end projects, Solid Wood (Oak, Walnut, or Cherry) offers unmatched longevity and premium feel. For commercial or high-traffic areas, prioritize HPL (High-Pressure Laminate) or Melamine-faced boards due to their superior scratch resistance and impact durability.