Pokémon have always had various ways of evolving into new beasties, and Pokémon Sword and Shield are no different. One of these curious contenders is the easily overlooked Milcery, which can be found primarily on Route 4, just south of the town of Turffield. You won't see them in the overworld walking about, so you'll have to look out for exclamation marks in the fields of grain.
Now there's actually a small clue for how to evolve Milcery into an Alcremie, but it's so subtle that unless you really know your Pokémon onions you'll likely miss it entirely. What you'll need to do is get your hands on one of many kinds of sweet, which you can do by battling (and winning) in one of the Battle Cafés found in Galar. There's one in Motostoke, Hammerlocke, and Wyndon, so take your pick.
When you've got one of these sweets, give it to your Milcery to hold like any other held item. Now here's the weird bit; you need to spin the left analogue stick around a few times until your character starts twirling on the spot. No, really.
Once you've done that, your Milcery will begin to evolve into an Alcremie! But hang on there just a blinking moment, there are various different forms of Alcremie to consider. How on Earth do you choose which one you want? Well, there are a few factors to consider, such as the time of day, whether you spin clockwise, anticlockwise, and for how long. One thing we can say for sure is that the sweet you give Milcery will be the sweet that adorns your Alcremie's... well, we think they're ears.