Stephen Hackett gives a rundown of the 10 different Watch faces:

While having so many options is great, many of the faces have frustrating limitations in the ways they can be customized or used.

Agreed: I’d love to get more ability to customize / swap-out different elements from different faces. But that’s just a minor quibble, really. About five days in with my Watch, and the faces are hands down one of my favorite features.

I’ve been mostly using the Utility face with the most basic detail allowable, activity rings in the upper left and current temp in the upper right. Then I’ll customize the color of the second hand and the date depending on what I’m wearing. Kinda dorky? Sure. But why not have fun with it?

The Modular and X-Large faces are also pretty fantastic. And I had no idea about just how interactive and cool the Astronomy face is.

Stephen Hackett On Apple Watch faces