Starting your own business that manufactures, retails, and installs custom-made interior French doors is an excellent way to be self-employed and generate very lucrative profit returns. There is very little competition in this business; yet the demand for high quality and unique French doors is very good, especially in the higher-end markets, such as expensive homes and professional offices. A great way to work with homeubilders who are prepared to offer your French doors to their clients as an upgrade finishing option. Design tip: To make your custom French doors unique and different from your competitors, you may want to consider a few of the following: Gold-plated or solid brass hardware, stained glass or sandblasted glass lites, stainless steel or mosaic tile covers, and curved or shaped tops. One thing is for sure: this business will allow you to be creative in your designs, which can assist you in building a solid reputation and client base.