The Warrior standing stone grants the ability to learn combat skills 20% faster. Combat Skills include: Smithing.

What Stone increases smithing?

In order to maximize skill gains when crafting, it is recommended to visit the Warrior Stone prior to smithing, the Thief Stone prior to alchemy and the Mage Stone prior to enchanting, respectively.

Does improving weapons increase smithing?

Using a grindstone increases your Smithing level, although to a lesser degree than actually forging a weapon. Appropriate metal ingots are required to upgrade each item (i.e., Ebony Ingot for an Ebony Sword).