Mine (new, now I have enough space for it!)
* Check every bird before accepting delivery - vent and breastbone myself, never rely on seller.
* I have multiple & divided carry boxes and try not to mix birds from sellers on the day of the sale (requires a sherpa - my wife

* Quarantine cage, keeping birds from different sellers in different cages where possible
* Good seed, plenty of grit and water for 2-3 days. Haven't used electrolyte mixes yet but now I can effectively use them I'm going to get some.
* Worm with moxydectin plus after 3-4 days
* Move in to quarantine flight after 1 more week (just a bigger cage really), mix different breeders birds up at this stage. I am now ringing every bird before it goes into the flight so I can still tell who is who.
* Move to main flights after a few more days and weather is good, move all quarantined birds at once so that one at a time isn't being introduced to the colony.