Cada quien

Cada quien literally means each person and is often used in utterances that emphasize the individuality of each of us:

• Cada quien tiene lo suyo. Everyone has their charms. The idea here is that each personally individually has their (possibly unique) charms.
• Yo creo que cada quien puede hacer lo que quiera. I think that everyone can do whatever they want.
• Cada quien habla de cómo le va/fue en la feria is a common expression you can say when each person, despite having participated in the same shared event, had a different experience. Some had a good time; others didn't.

To Each His Own

As a stand-alone expression, cada quien expresses the idea that we're all entitled to have different preferences, to live our life the best way we see fit.

• Pues cada quien, ¿no? Different strokes for different folks, right? Said when encouraging someone to not get upset at someone else for making different life choices.
• You don't like sushi? What?! Pues cada quien. Well, that's kind of weird but I accept your preferences even though they're not mine.