If your watch app has good VoiceOver support, chances are you'll also have good Assistive Touch support. But an improvement you can make is to implement a quick action (triggered with a double pinch) when there is a main action you can perform.

Assistive Touch for the Apple Watch works like magic. It lets you use your watch with gestures with the hand of the same arm you are wearing your watch on. No need to use your nose! If you don't have it on, is because you don't know about it.