French doors often open out towards a patio or are used to close one room off from another.  Because of their beauty, the right French door shades can really add a nice decorative touch to any room.  Options for your French door shades include both curtains and sheers.  Sheers are great if you don't want to completely block off your view while curtains will often do that.

You will have greater fabric options than sheers but both are a good choice.  Other French door shades to consider are actually door blinds.  If you choose blinds for your patio doors, keep in mind they will require a low profile head rail and bottom brackets to hold them in place so they don't bang every time the doors are opened and closed.

Finally, you can choose French door pleated shades.  These can often be lifted and lowered from both the top and bottom which makes them a perfect choice for maximum light as well as privacy.  No matter what you select, keep functionality in mind.  Any of the above is worth considering.