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.

Home improvement stores: Home Depot, Lowe’s (pre-primed options). Lumberyards: For custom wood profiles. Online: Etsy, eBay (for vintage millwork).

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