Formal:
* Comment s'est passée votre journée ? (How did your day go?) - This is the most common and formal way to ask.
* Qu'avez-vous fait aujourd'hui ? (What did you do today?) - This is also formal and focuses on the activities of the day.
Informal:
* Comment ça va aujourd'hui ? (How are you doing today?) - This is a more casual way to ask.
* Et toi, comment a été ta journée ? (And you, how was your day?) - This is informal and assumes a friendly relationship.
* C'était quoi, ton truc aujourd'hui ? (What was your thing today?) - This is very casual and implies you are curious about what happened.
Other options:
* Bonne journée ? (Good day?) - This is a simple way to ask, but it might sound abrupt.
* Alors, la journée ? (So, the day?) - This is also a simple way to ask, and it's more informal than the first two options.
Remember to choose the option that best suits the situation and your relationship with the person you are speaking to.