Hu Tao is a predominantly Charged Attack focused DPS who best synergizes in teams with sufficient off-field Hydro application which allow her to Vaporize all of her Charged Attack hits.
When ending Hu Tao's combos with a Burst, if you do not jump/dash cancel the last Charged Attack, the Burst still benefit from Hu Tao's Skill.
It is recommended to use cancels when performing your Hu Tao combos as to maximize damage.
for [C0] and for [C1]. can be used to conserve stamina at the cost of damage.
Regarding Weapon Choices:
Staff of the Scarlet Sands: When using this weapon, (4) becomes competitive with (4) for being Hu Tao's best artifact set.
Ballad of the Fjords: At [R5], this weapon is better than .
Deathmatch: This weapon is better than when you're not doing Vaporize.
Primordial Jade Winged-Spear: Is better than the [R1] variants of and with ideal stacking. While this is a very strong weapon when fully stacked, maintaining the stacks on Hu Tao isn't ideal in realistic situations making the weapon less consistent than other options.
Lithic Spear: At [R5], this weapon is better than .
White Tassel: This weapon prefers an combo over an combo.
Blackcliff Pole: Despite seeming quite good due to the CRIT DMG substat, at 1 stack performs only slightly better than an [R5] in practice as it is difficult to maintain stacks consistently. It is not recommended to buy this weapon specifically for Hu Tao and should only be used if you already have one.
Regarding Artifact Choices:
Sets
Shimenawa's Reminiscence (4): Provides higher Normal Attack and Charged Attack damage than (4), but reduces Burst damage, impacting overall AoE damage. Additionally, if you're unable to Burst, it might lead to survivability issues unless you're running a healer.
Gilded Dreams (4): At 3 Elemental Mastery stacks, this artifact set is equal to (4) in teams where you are not getting Elemental Mastery from other sources (e.g team or weapon).
Marechaussee Hunter (4): This is Hu Tao's best set when you can reliably get 3 stacks, which typically requires running Furina, or healer that can heal smaller amounts over time (i.e. Xianyun, Chevreuse).
Substats
Elemental Mastery: Since Hu Tao is able to trigger Vaporize on most of her damage output, Elemental Mastery is quite valuable on her. If you have less than 100EM total (including from Sucrose's Elemental Mastery share, (4), etc) Elemental Mastery substats take priority over CRIT Rate / CRIT DMG.