Pottery is the most unused. Not overlooked, but ignored with a good reason. Clear glass furniture and tools are more valuable and faster to make. You can glaze anything really. It works like encrusting. Metal industry can provide even more valuable products.
Automation is the most overlooked, as people think about mine-carts and quantum stockpiles, as an exploit, then a manager's options extension. I automate everything from very start of embark. The only things I do manually still, is:
- cooking, because it is so cumbersome for food variety
- any activity with pastured animals (milking, sheering, breeding for skins and meat), as animals husbandry can not be automated
- milling dies into bags (50-100 jobs at a time), as for some reason manager can not detect any dies in existence
Some industries go idle after a while. Soap maker is one going idle from the beginning of the game. 100 soap bars will last for ever.
Metal industry grinds to a halt after all master quality armor and weapons been made.
Jewelry is a side production on side of mining. Encrusting serves I feel no purpose to differ from glazing all pots, as that paints pots in one uniform color.
Only industries that go forever are (because Dwarves are consuming those):
- died clothes industry (wear)
- booze industry (drink)
- mead & royal jelly various flours roasts industry (drink & eat)
- one could set automated cooking of food too, if particularly bend on designing linked stockpiles. I just buy all ingredients from caravan for food variety sake.