What you choose for your French doors will depend on your style and how much privacy you need. Sheer or solid drapes may fit on the doors with some handy sewing work. Fabric panels pleat onto thin curtain rods that screw in place at the top and bottom of the window panels. They are secure and hold up well to frequent door use. You can also buy blinds that cover French doors. They can open or close like other blinds, which is an advantage over fabric panels. Another option is window film. This material is easy to DIY and comes in finishes that resemble frosted or stained glass.