I turn on more magma glass forges, set them to make raw green glass, then decorate every friggin' object in my entire fort with spikes of green glass. If you have magma and sand, you have an infinitely extensible industrial base.
I can also reactivate some extra farm tiles, farmer's workshops, looms, dyer's workshops, and clothier's workshops (setting them to decorate and make bags, because I have too much crap in my warehouses, anyway). If you have soil, you have unlimited access to expanding your textile production.
I can set a whole bunch of laborers to mechanics, create some mechanic workshops, and make them go to town on my rediculously overstocked stone warehouses. I then have a collection of levers that I hook up to something like a cage, so that I can make the mechanisms dissapear into levers, and not take up any space.
I can set them all to mason, and just do something crazy/stupid, like walling in another large chunk of my nearby forested land so that I have a protected tree harvesting area, or for that matter, start work on some kind of megaproject like building a tower for an orbital magma launcher.
I can just set up some screw pumps connected to nothing, and make a gym. (Made from green glass.)
When all else fails, I just put them in something really stupid, like the Royal Guard.