The roman blinds hung from the ceiling is a great trick to make the windows seem bigger, but either drapes + sheers or drapes + romans works well (not drapes + sheers + romans).
Sheers plus heavier drapes hung from ceiling with lower window work well to maintain the height of the room.
Curtains in similar tones to patterned pendant shade.
An example of what not to do: the curtains should be hung from the ceiling, not above the window, and the rod should be full length. This cuts the room off.
Covered curtain rod
Sheers + patterned drapes (this pattern is too bold but still interesting to see it combined with sheers)
Sophisticated, more subtle pattern... more relaxing
Nice curtain length on a mid size window (left window), a more voluminous material gives a softer, more casual feel. Heavier drapes that hang straight are more formal/modern.
Alternative: hang romans inside window frame, hang curtains from ceiling. Two-tone curtains are lovely.
A fresh take on the two-tone curtains: sheers on top 1/3 and heavier drapery on the bottom 2/3.
Here a very subtle two-tone curtain ties the wall and chair colours together (this could be done using your wall and pendant shade colour).
The curtains are the feature of this room. They are lovely but would overpower a gorgeous patterned lampshade. With a plain lampshade and relatively calm decor, they add just the right amount of interest.
A well balanced contrast between dark and light in this dining room