I'm so honored to be a guest here today! (I'm Eva from otis & frank) I thought I'd add a few of my humble thoughts to the renovation that is currently happening around here...so here it goes:
Painting the interior trim of your windows black. It's a big step but can really make the windows a focal point.
A big mirror (possibly between your two tall gorgeous windows), adds some dimension and space to the room.
Big pendant light fixtures over work spaces, I love these in black or white...
If there is space, two tables or desks facing each other double the amount of workspace and create symmetry in the space.
Storage units (the large Expedit from Ikea is perfect), mounted onto casters so they can be used as room dividers or reconfigured as needed.
Pops of color, inspiration boards along the wall
A long floating work station built-in
Tons of tall storage, these bookshelves are great because they wrap around both corners, and again, I'm a sucker for symmetry.
Neutral colors for the walls and furniture, but painting pops of color inside storage units and in accessories. I love this gray and orange combo.
Some good (cheaper) Ikea options: the PS Cabinet, the Hovet mirror, Expedit shelves, and instead of desks, kitchen units (like the Varde) might have more storage and be a good standing height for a working in a studio.
photos via Living Etc., Domino, and Elle Decor.