Activate Ghired by tapping it, creating a copy of the Fear of Missing Out token.
When the Fear of Missing Out token enters the battlefield, it triggers, causing you to rummage.
Move to your combat phase and declare the Fear of Missing Out token as an attacker.
The Fear of Missing Out token triggers, untapping Ghired and causing you to get an additional combat phase after this one.
Repeat from step 2.
This loop turns a simple combat trigger into an endless stream of extra phases by constantly refreshing your board with fresh copies of Fear of Missing Out. Every time a new copy enters, its rummaging ability lets you filter your hand while Ghired, Mirror of the Wilds leverages its activated ability to tap and replicate that incoming token using the haste granted by Frostcliff Siege's Temur mode. When you declare attackers, the token's delirium attack trigger untaps Ghired and tacks on an additional combat phase, allowing you to instantly repeat the entire cycle.