The best curtains for your sliding door will fit nicely around the outer frame. They'll also ideally have good tiebacks that can hold them back while allowing easy access to the door handle. As an alternate option to two panels of sliding door curtains, you could use a pull-up type of fabric panel such as a Roman blind. This way, you won't have to attach tie backs to the sides of the sliding door. Whatever type of sliding door curtains you choose, being able to access the doorway without feeling obstructed by window covering material is crucial.
In general, a sliding door isn't the place to feature ample, romantic curtains that puddle on the floor. It's likely that such excess fabric would become damaged easily from being walked on, since sliding glass doors are entryways. Flowing fabric panels used for sliding door curtains may also become drawn through the doorway when it's being opened or closed.
A Roman blind curtain adds a sleek, clean-lined look, as it's a flat, single piece of material. This type of window covering can be an ideal choice for a modern, uncluttered interior design style, and it's not likely to be tread on or caught in the door. A printed, colorful fabric used for sliding door curtains can also add a lot of interest and style. It's a good idea to use a neutral-colored lining so that is what will show from the outer side of the sliding glass door.
Another style to consider is one with streamlined, softly pleated panels that attach to a rod with eyelets or rings. A decorative curtain rod and features such as metal eyelet holes or wooden rings with clips can give interest to a basic sliding door. You could choose either solid or printed fabric for these sliding door curtains, depending on your preference and what will work best with the rest of the decor.
Sheer curtains with a blind underneath may also work well for a sliding glass door. With tiebacks on either side of the door, sheer sliding door curtains can be opened to reveal the view or perhaps an interesting blind for privacy, such as one made from bamboo or wood. When less privacy is needed, the blind could be left rolled up and the sheer curtains could hang across the glass to filter sunlight.