I assume the windows abut in the corner? This would make it tricky to have romans as they would probably clash when both drawn up. Curtains drawing away from the corners add softness to a dining area, but make them floor length as short curtains look a bit half mast. It is also a good idea to have them wider than the windows to allow more light in when opened and fitted from above the window to elongate the window.

I'd like to suggest that the most important thing here is more about who is using the room. If It's a child's bedroom use lovely children's curtains - there's so much around and any pattern could pick up the wall and floor colours. If a guest room and not used often I'd suggest a beautiful velvet or good quality Linen and forbid the little ones from going in to that room!!!!!! alternately a blind attached at floor level could be raised or lowered so the view is still there but with privacy from waist height perhaps. Good luck. Bee

How about a curtain track below the window?

You can certainly have different curtains in each room. That way each room will have it's own personality, but the important thing is that they relate to each other in some way. It's good to keep the weight or type of fabric used consistent (maybe they're all linen - but in plain, stripe & pattern). Think - "variation on a theme"