Activate Pili-Pala by tapping it, adding {G}{G}.
Activate Pili-Pala by paying {2} and untapping it, adding one mana of any color.
Repeat.

Infinite colored mana

Pili-Pala

Careful Cultivation

Activate Farmstead Gleaner by tapping it, adding {G}{G}.
Activate Farmstead Gleaner by paying {2} and untapping it, putting a +1/+1 counter on it.
Repeat.

Infinite +1/+1 counters on Farmstead Gleaner

Farmstead Gleaner

Activate the creature with Careful Cultivation and Umbral Mantle attached by tapping it, adding {G}{G}.
Activate the creature by paying at most {2} and untapping it, causing it to get +2/+2 until end of turn.
Repeat.
If Agatha of the Vile Cauldron has power 2 or greater, this combo nets infinite green mana.

Infinite green mana

Infinite power and toughness for a creature until end of turn

Infinite untap of creatures you control

Infinite mana creatures you control can produce

Infinitely large creature until end of turn

Umbral Mantle

Agatha of the Vile Cauldron

Activate the creature with Careful Cultivation and Sword of the Paruns attached by tapping it, adding {G}{G}.
Activate Sword of the Paruns by paying {1}, untapping the creature.
Repeat.

Sword of the Paruns

Zirda, the Dawnwaker

Activate Yenna by paying {2} and tapping it, creating a copy of Airtight Alibi attached to Yenna, and then untapping Yenna and causing you to scry 2.
When the Airtight Alibi token enters, it triggers. Holding priority, activate Yenna by tapping it, adding {G}{G}.
Resolve the Airtight Alibi trigger, untapping Yenna.
Activate Thaumatog by sacrificing the Airtight Alibi token.
Repeat.

Infinite lifegain triggers

Infinite lifegain

Infinite scry 2

Infinitely large Thaumatog until end of turn

Yenna, Redtooth Regent

Airtight Alibi

Thaumatog

Activate Veteran of the Depths by tapping it, adding {G}{G}.
Veteran of the Depths triggers, putting a +1/+1 counter on itself.
Animation Module triggers, causing you to pay {1} to create a 1/1 Servo artifact creature token.
Intruder Alarm triggers, untapping all creatures.
Repeat.

Infinite creature tokens

Infinite ETB

Infinitely large Veteran of the Depths

Veteran of the Depths

Animation Module

Intruder Alarm

Activate Rona by tapping it, adding {G}{G}.
Cast Rograkh by paying {0}.
Rona triggers, untapping itself.
Activate Temur Sabertooth by paying {1}{G}, returning Rograkh from the battlefield to your hand.
Repeat.

Combos with "Careful Cultivation"