I measured, scored, cut & screwed in a piece of drywall:
I measured, cut (with a chop saw) and nailed in a frame for a window seat:
And it's sturdy! So, we'll be getting some nice wood sheets to finish them and we'll be making it storage inside too.
There's one of these in each of the 2 smaller bedrooms.
I had to cut the 6 pieces that aren't resting on a 2x4 at different heights than the 6 pieces that are and I figured out the top frame part too - it's beautiful =) It was a lot of work, not really, but I don't do this sort of thing regularly. . . . so, yeah - I'm proud!