I have just finished working out how my castle windows will be built and decided to create some instructions.
As with my panelled castle doors, I have inset the window frames by half a stud allowing for a 1x4x2 arch to sit proud of the wall by half a stud at the top. The window opening is detailed with quoins and a curved 1×2 tile above the arch.
As with any of my instructions, please let me know if they are useful to you. I would love to see what you do with them!