If you have a garage or work building and are willing to learn a craft, upholstering, re-upholstering and/or furniture refinishing would make an excellent home business. The investment is comparatively small and there is always a market for these skills and the products they yield.
if you do not already know how to upholster or refinish wood, the first priority is to learn how. If you are experienced, you can begin with small projects and work your way up to the more complex and better paying jobs.
In the case of a husband and wife, one could specialize in each to provide a complete service! Learning these crafts starts with reading, then practicing. If possible, get a job working in the field to learn direct from the professionals. Otherwise, there are schools, courses and hundreds of books covering every possible aspect of furniture upholstery and refinishing.