My third spiral design. #2 was too big, lead to degradation in FPS after a while. Rotate 90 degrees clockwise each level down. The large areas are rounded workshop rooms, hopefully the smaller size will help keep pathfinding costs lower.
Other than FPS, the primary advantages of this layout are that, depending on the rotation and state of designation or digging, you can imagine it as a heart, a smiley face, a pair of breasts, a pair of testes, or the International Space Station. Your own personal preferences may come into play too, for example, I see the ISS with a pair of breasts, but maybe that's TMI.
The "solar panels" are bedrooms or small workshop rooms, and the "breasts" are large workshop and stockpile areas. You could make each level a burrow with a small food and drink stockpile if you wanted, too. As you can see, I've made this level a cloth-related level. The stockpile is actually one big stockpile, then with notches cut out for the empty area, and small notches cut out around the dyer's shop for a dye stockpile. The bedrooms on this level haven't been decorated yet.
As you can see, I have a strange mood going on here. Let's hope it turns out well, and produces an actual good artifact, this fort has had precious few of those so far. Edit: Got a pig tail left glove...
Worth 25k.