MDF: Affordable, paint-ready, but not moisture-resistant. Solid Wood: More durable, stainable, but pricier and can warp. PVC: Best for bathrooms (waterproof).

Use a miter saw: Set to 45° for standard corners. Coping method: For tight inside corners, cut one piece straight and "cope" the mating piece. Test cuts: Always check fit before nailing.

Yes, but: Sand down high spots or use construction adhesive for extra hold. Consider backer rod behind moulding to fill uneven gaps before caulking.