One of the micromanaging tasks that gets to me while playing DF is the necessity to micromanage which miners are currently hacking their way through each piece of stone.
For instance, I've got a pair of legendary miners, and I want only them to extract gemstones and high-value ore (my only galena vein, for instance). On the other hand, I don't mind if my soldiers-in-training (dabbling miners all) take their time cutting yet another block of dwarven apartments out of conglomerate.
What I'd like to see is an order, similar to that which you can set on various workshops. On a workshop, you can require that only dwarves with a skill rating between a given minimum and maximum be allowed to work there, so you can easily make it so that only Legendary [X]smiths work at the Metalsmith's Forge where you're ordering up your fortress's armor.
I envision it as an order screen similar to the stockpile / stone screen, where you can set a minimum skill required and a maximum skill allowed to mine for either all stones of a particular type (Gem, Ore, Economic, Other) or for each individual type (I've got enough magnetite to last a thousand years, but I'm short on malachite).
Then, I wouldn't need to babysit my gem and rare ore veins and clusters, repeatedly designating and undesignating each square until the right mix of miners shows up.