>Recycle allows the user to regain a held item, such as a Berry, once it has been consumed. Consumed items are not forgotten when the Pokémon is switched out. Recycle can recover items consumed by Fling and Natural Gift, and but not items lost by Thief, Covet, Trick, Switcheroo, or Bestow. Recycle will also fail if the item is collected by a Pokémon with Pickpocket.
Recycle can recover items consumed that were originally another Pokémon's, but transferred to the Pokémon with Recycle via Thief, Covet, Trick, Switcheroo, Bestow, or Pickpocket. However, a Pokémon may only have one consumed item at a time; if a Pokémon consumes an item, obtains another and consumes it, the original consumed item cannot be restored, even if the second item is restored and swapped away.
That should answer the trick/natural gift/fling/switching part :P
And I think copycat/mimic/sleep talk/metronome/assist on Recycle would have the exact same affect. Providing you have consumed an item and stuff.