for the interior doors. pre-cut molding for flat doors -- I have done this to one of my doors (except I made the molding myself) and it looks great. I think a pre-made kit is a great idea!
Wandlamp Elay - 18x20x19 - hout naturel - industrieel groen - Light
DIY: How to Dress Up a Plain Luan Door - great beginner's project shows how to turn a plain door into a rustic farmhouse door using underlayment - ia The Wood Grain Cottage, via Infarrently Creative