In Pokémon GO, you can now earn XL candies in a new way. This is especially worthwhile for rare Pokémon, where these candies are particularly in demand.
What’s new: On reddit, trainers have shared a new method for obtaining the coveted XL candies: by feeding Pokémon in gyms.
There, an XL candy is now expected to be occasionally issued. This is particularly interesting for rare Pokémon, for which it was previously difficult to obtain XL candies.
The new method to earn XL candies
What you should know about the new method: In general, feeding Pokémon occasionally yields a regular candy as a reward. Now, there should also be XL candies available through feeding.
However, keep in mind that the chance of receiving a regular candy when feeding is already quite low. Thus, the chance of an XL candy is likely not better. You will need many berries and some luck to receive XL candies.

What you should do now: Even though the chance of getting XL candies through feeding is low, you should take advantage of this method of candy acquisition.
So primarily place rare Pokémon in gyms for which you’d like to receive XL candies and feed them several times a day. This way, you might get a few XL candies with some luck.
Why the new method is so good: By feeding Pokémon in gyms, you can especially obtain XL candies from the monsters that are otherwise very rare.
So far, these candies are only obtainable through hatching and catching Pokémon. Monsters like Milza or Kapuno are hardly hatched or caught. So the chance of many XL candies is low. Now you can at least receive a few XL candies for such Pokémon.
You should have chances for XL candies from Kaumalat at the next event in Pokémon GO. However, trainers already have doubts about that:
Pokémon GO: Players are already worried about a bonus from the Sinnoh event