One of my favorite new features of the Apple Watch Ultra is the Precision Start mode for the Workout app. With this mode, your workout won’t automatically start with the 3-2-1 countdown. It will start when you start it. This works great for workouts that require a GPS lock because the Apple Watch will get the GPS signal. This means no more jittery maps as you start your run or walk.
It took me a while to find how to enable the mode. You do it in the Watch app on your iPhone. Within there, go to the Workout section and enable Precision Start: