What are some of the more commonly-used methods for converting a pony to a changeling? I'm playing around with an idea where that comes up as a topic of conversation, and I need multiple possible options for the discussion - at least five, but preferably more.

One would be pods, another could be by bite or even a spell it also could be eating a changeling turns you into one, just a few suggestions.

I've been partial to the pod system,
I've seen the royal jelly treatment done well in another story

as an alternate idea, their love energy could be drained without a pod, leaving them close to death, (or not) and either a spell or royal jelly could be used (or nothing) to replace it

possibly it could be a disguise spell they cast on themselves that had the side effect of destroying their ability to generate love energy on their own

no matter what I think of, it pretty much comes down to combinations of pod/open air, spell/food, draining their love to nothing

6467933
1) Conversion pods
2) Replaced, memory copied over without clone noticing a thing
3) Queen magic
4) haha Changeling all along

6467933 The changelings are actually the only species in the world. They're just pretending to make things more interesting.

The pony wasn't a pony at all. There's actually no such thing as a pony. There are only changelings everywhere.

Have you read " Integration " by Raugos? At this point most already have, that fic is a masterpiece on it's own, but it also really goes deep into the topic of a pony becoming a changeling. 10/10 also has a narration on You Tube by Thornquil.

6467937 I've done it by a spell. In one story, Twilight (under the changeling queen's mind control) invented a spell to do it; in another I've plotted but not written, the spell has been kept secret by the changelings and the ponies have long forgotten it exists.

In my mind, the pods converting ponies to changelings is antithetical to their draining love - and there's no reason Chrysalis would've wanted to convert the Mane Six and the Princesses into changelings.