You will need 9 Teachings of Diligence and 63 Guides for Diligence to fully develop your Hu Tao’s talents. 114 Philosophies of Diligence is also required.
Apart from Nectar bottles that you can earn by killing Whopperflowers (which is also how you will be earning them), there will be some domains to help Hu Tao with his talent materials. You can earn Diligence books by completing Taishan Mansion’s domain on Mondays. For Shards of a Fol Legacy, you will need to defeat the Childe boss. Crowns of Insight are available through limited-time events and by offering your sacrifices to the Frostbearing tree and the Sacred Sakura. Visit https://entrepreneursbreak.com/hu-taos-fascinating-facts-and-a-few-questions-to-improve-your-walkthrough.html before reading this.

Although all of Hu Tao’s talents are essential to her build, you will likely want to prioritize her Elmental Skill as this is where most her damage comes. It’s best to level her Normal attack, but don’t let her Elmental Burst fall behind, as this heals her HP that she’ll lose through using her Skill. This is Hu Tao’s entire repertoire:
Normal Attack — Performs up six consecutive spear strikes. Charged Attack – Uses a certain amount Stamina to move forward and deals damage to all enemies. Plunging Attack- Drops from midair to strike the ground below. This can cause damage to opponents and deal AoE DMG on impact. Elemental Skill – Hu Tao uses a portion of her HP to knock out nearby enemies and enter the Paramita Papalio State. Paramita Papilio: Hu Tao’s ATK is increased based on her Max HP when she enters this state. The Hu Tao Base ATK cannot be exceeded by the ATK Bonus. Hu Tao’s attack DMG has been converted to Pyro DMG. This elemental infusion cannot override. This increases Hu Tao’s resistance against interruption. The Blood Blossom effect is applied to enemies by Hu Tao’s Charged Attacks in the Paramita Papalio state. Blood Blossom Effect: Enemies that are affected by Blood Blossom will receive Pyro DMG every four hours. This DMG is Elemental Skill DMG. Only one Blood Blossom effect can be applied to each enemy at a given time. The duration of the effect may be extended by Hu Tao. Paramita Papilio ceases when the duration ends or Hu Tao is gone or has fallen. Elemental Burst – Hu Tao commands an energizing spirit to deal with Pyro DMG in large AoE. Recovers a portion of Hu Tao’s max HP upon striking an enemy. This effect can be activated up to five times depending on how many enemies are hit. Hu Tao’s HP must be below 50% to trigger the DMG or HP Regeneration.