Using Giant’s Toes & Wheat
Giant’s Toes and Wheat. These are the keys to Alchemy leveling. Combining these two easily-obtainable ingredients yields one of the highest value potions and is quite possibly the quickest and easiest way to level up your Alchemy skill.
Giant’s Toes are especially valuable in the Alchemy process, so put aside your inner pacifist and slaughter every walking skyscraper you see during your travels. Giant camps are marked by Mammoth Skulls on your map. If you haven’t found any yet, there are two camps right next to each other in the valley between Whiterun and Windhelm, as seen below:
You can also sometimes find Giant’s Toes for sale at Alchemy shops.
Lots of wheat can be found at the Brandy Mug, Hlaalu, and Hollyfrost farms, all found immediately east-southeast of Windhelm, and all are very near each other. Harvesting wheat from these fields is not a crime, and in no time you’ll have more than you know what to do with.
Adding a Creep Cluster to the mix gives you one of the most valuable mixtures in the game, though it’s only about 30% more valuable than the meat and potatoes mixture of, uh, wheat and gigan-toes, and obviously requires procuring a third ingredient. However, if you wish to do the extra legwork, Creep Clusters are quite abundant and can be found by starting at Windhelm and heading south by foot. You’ll find some on the rocks beside the round, near the geysers south of Bonestrewn Crest, around the Atronach Stone (directly south of Bonestrewn Crest), and around the Riverside Shack.
Note that because Wheat and Creep Clusters are so extremely abundant and easily obtained for free, you can forego the Giant’s Toes and just add these two ingredients. Granted, the resulting potion is not nearly as valuable as the above combinations, but hey, quantity over quality. Or something like that.
Buying Out Shops
If you’re tired of tracking down Giant’s Toes, an alternative method to quick levelling is to find any Alchemist, buy out all of their stock, create potions like a mad scientist, then sell everything you’ve made back to the vendor to get your original gold back.