Random ideas
Materials: Ironbone, Bloodsteel, Ebonyglass/Ebonglass, (I think its in the orc fort raws already) Slade
Weapons: Dagger, swords, scimitars, whips, glaives
Armor: Weak armor. Using only chainmail would be a change from other races for example.
Poisons. Lots of them.
Drider, Drow+Spider, transformation
Spiderfarm, either for silk, for poison, for warbeasts or all of this.
Curses and Voodoo. Make a super-expensive reaction for a "goblin voodoo", run "slayrace goblin".
Albino-Drow caste that is rare, but has access to special interactions.
Head of state should be female only, monarch called Matriach.
A bonus linked to cave adaption. Or more precisely: A heavy nerf based on non-cave-adaption. Drow that go out into the sun get heavy penalties and slowly go back to their normal, drow self after a month or two underground. Something like only 10% speed or so, something really major. This should lead to the new tactic of luring enemy invasions completely underground before engaging them in combat. Same counts for traders, people would build trader-tunnels into their fort, instead of having a half-aboveground area of their fort. It would also make access to wood harder, so that people rather fell fungis in the caverns then go to the surface. All in all, I really like that idea, because it is relatively simple to do in the raws, but has a major effect on gameplay and fortress design.
By the way, I dont know much about DnD Drow either. They were suggested to me when I asked around about a possibly evil trade race.
Last thing: The drow graphics I use are not how DnD (or anyone else) despicts drow. So if you want to give them a more pale-elf-in-purple-clothing style, feel free. The current ones look like red-eyed, darkskinned dwarves. ^^