There and Back Again has exactly two lore counters on it.
Steps
At the beginning of your precombat main phase, There and Back Again triggers, putting a lore counter on it.
There and Back Again's third chapter ability triggers, creating a legendary 6/6 Smaug creature token and causing you to sacrifice There and Back Again.
Activate Ghired by tapping it, creating a copy of the Smaug token.
Put either Smaug token into your graveyard due to the legend rule.
When the Smaug token dies, it triggers, creating fourteen Treasure tokens.
Activate four Treasure tokens by tapping and sacrificing them, adding ({4} magic symbol) .
Activate Staff of Domination's third ability by paying ({3} magic symbol) , untapping Ghired.
Activate Staff of Domination's first ability by paying ({1} magic symbol) , untapping it.
Repeat from step 3.
Notes
Once you have infinite mana, you may instead use Ghired to copy any other token(s) that entered the battlefield under your control this turn. You may also use the mana to activate Staff of Domination's abilities any number of times.
Results
Infinite LTB.
Infinite ETB.
Infinite colored mana.
Infinite death triggers.
Infinite lifegain triggers.
Infinite lifegain.
Infinite card draw.
Infinite untap of creatures you control.
Infinite draw triggers.
Infinite mana creatures you control can produce.
Infinite Treasure tokens.
Infinite copies of tokens you control that entered the battlefield this turn.