Just last week, we shared a newly-found item duplication glitch within Animal Crossing: New Horizons which allows players to infinitely copy any 2x1 items. That wasn't the first glitch of its kind to be discovered - Nintendo actually patched out a glitch that was found early on - but now we have yet another one to try.
This time, the new glitch has been discovered by YouTube user Do Whatever Games. In the video below, they explain how you can use the game's mail system to duplicate any item which can be sent to friends as a present.
You'll need to have two or more other players registered on your island, so that's three including yourself, and you'll want to send your chosen items (Do Whatever Games recommends sending 1-3 things at a time) to one of them through the mail. Once that's arrived, you'll need to use the Call Resident app on your NookPhone to get the mail recipient player in-game alongside you.
Make the mail recipient the leader, and have them open up their mail. They should open the presents and drop the items on the ground, after which you should immediately use the Call Resident app once again to play with a different player instead of your mail recipient. Once they've popped in to the game, end the session; you should find that the items are still on the ground, and that if you repeat the process, your mail recipient will still have those items in their mailbox, ready for you to do the whole thing over and over again.
If you're feeling a little confused, make sure to watch the video above to see all of this in action. It's quite possible that Nintendo will patch this out in the near future, so you should probably think about trying this soon if you don't mind cheating the system a little.