Many wood mouldings can be bought at reasonable cost from lumber yards and can be used as the basic product for manufacturing frames. Everyone has photos and prized possessions which need framing. Many people don't like the plastic frames found in stores today, thus creating a ready market for beautiful, natural wood frames. Quite often you can find old, beautiful, rugged picture frames at rummage or garage sales. They can be repaired and cut down to today's standards.
Good frames can add substantially to the value of art, paintings, posters, certificates, etc.
The list is endless. No matter where you live you can start a picture framing business. To some, it can be an exciting and fascinating trade. With just a little experience and proper tools you can also learn to cut your own glass for the frames. You local library may be a great source of information on the subject.