Match the other 2 windows with blinds and put panels on all 3 windows.

Agree that the window treatments should be the same for all windows in the room.

Not necessary all the same window treatments.

I like to go with panel curtains with the same height.

Here is an example how to go with mismatching shades and blinds like a pro.

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Curtains will be difficult with the slope of the ceiling, however, Roman shades would look nice.

You could also do blinds to match your other windows and add a simple decorative fabric valance across the top of the window.

Celery's first rendering with the grey curtains is wonderful. But do you want blinds for privacy or light control? If you only had curtains on that window, you'd have to close them all the way for light and privacy. I'd get top down bottom up cellulars and get grey curtains.

Here is roman shades with panels mix.

Another option to go with both

I like the clean looks you have in this room, and I appreciate that the wood trim is not covered. Get the same wood blinds for the large window unit...maybe motorized because it will be a heavy unit. But keep your design...great job.