Use wood or ceramic nest eggs and collect often. Keep nesting boxes fairly dark. Removing the culprit permanently is sometimes needed.
I've lucked out mostly. The big girls will eat an egg if it gets broken in the nest but don't break them themselves. Oh boy. If I drop one it's like piranhas.
I did have a silkie hen who was an egg eater. She'd go out of her way to try and break open an egg. That started when another hen was having thin shelled eggs. She couldn't see them well enough to break them in the dark nest boxes and would follow me when I went to open the boxes to collect. She got dumped on her butt enough times but it didnt deter her.
Silkie stew?
Weasel got her. We have issues with them occasionally and she liked to sleep outside no matter how often I put her in