2. Another, more traditional option is to hang a thin curtain rod on top and bottom of each door panel, and hang sheers or silk shantung or muslin. This will provide some privacy, but still let light through. You can also cinch the middle with a matching sash, or one that coordinates with your room décor, when you need more light. Or keep it full for maximum coverage and privacy. You can purchase this type of curtain, or make it yourself. If you can't sew, take pre-measured, cut panels to a dry cleaner and ask if they will make a hem or curtain rod pocket, most dry cleaners will do this for minimal cost.
3. For no work on your part other than installation of the shades, try buying pre-made pleated shades or Roman shades that screen the light and protect the furniture. They'll add instant elegance to your French doors and can be easily removed and dry-cleaned, or raised when you want to let light in. This is a great option for almost any style of home or room décor, and you can dress them up or down as much as you want.
4. Try using a valance on top with a retractable screen or mini blind that you can let down when you want privacy and light control, and that you can raise when you want to see the view or let sun in. The valance is a great option because it covers the blinds when you do not want them to be seen. If a valance is not something you particularly like, try a cornice. It really does not matter, but you will likely want a window treatment that looks nice, is functional and will go with the décor in the rest of the house
5. Use simple fabrics, and dress up the door with substantial doorknobs and hardware adorning them. This is a great way to avoid the French door window treatment problem by simple changing the focus from the window treatments to the door itself.
French doors are beautiful additions to any home, so don't let the daunting challenge of window treatments sway you from installing a beautiful French door between your kitchen and patio.