The easiest way is to smith the most expensive items you can. Start by making jewelry. You can get the transmute ore spell relatively early in the game, which allows you to turn Iron ingots into Silver, and then Gold. Which allows you to make a bunch of silver and gold necklaces. Save all the gemstones you find and loot as well, to put into the jewelry you make. Jewelry aren’t the only expensive items you can craft; banded iron armor, and other chest peices tend to be fairly high priced as well. The more perks you have unlocked, the more options you have.
Outside of crafting the expensive stuff, your best bet would be keeping all the furs and ores you have and storing them away until you can use them, and seeking out Smithing Teachers.