I did not powerlevel smithing at all. I did not purchase a single material from a shopkeep. I brought a pickaxe with me and mined when I could along my journeys. I also tended to find a ton of jewels lying around in dungeons.
From just smelting the ore I mined myself, skinning the animals I killed myself, and making things with what I had, I hit 100 smithing before I hit 100 in anything else. I made so much money off jewelry alone it isn't funny. I think I hit 100 smithing around character level 35 or so.
I can't imagine if it were made any easier.