watchOS 7 offers a lot of cool watchfaces for use with your Apple Watch. But you add more. Here’s how to do it directly from the smartwatch:
° “Long press” the display. (In other words, press the Apple Watch screen and keep pressing.)
° Swipe left until you reach “New” and the “+” icon. Tap the icon.
° Scroll the Digital Crown to select the new watch face.
° Tap the watch face to select it.
(This how-to is based on my experiences and info on Apple’s support pages — where the images sometimes come from.)