Use and Customize the App Dock
The easiest way to open an application on your watch, or a commonly used application, in any case, is by using the base, which came with the watchOS 3 updates. This quick-start application selector is accessed by pressing the button side. Not the Digital Crown dial, but the button next to it.
Any application can live in the dock, regardless of whether it is pre-installed or created by a third party. The apps you put there are constantly being updated, so you can see a live preview when you swipe from side to side on the dock. Tapping an app from its live preview will launch it instantly (or almost instantly).
Switch Apple Watch Faces
You may want to set up multiple watch faces for multiple purposes: one with a minimal face for those times when you don't want a cluttered interface, the other with a more fun display. To switch from side to side, just swipe left and right from the watch face.
