Breaking out of autopilot brushwork

I caught myself last week painting a row of distant trees along the ridge behind my house, and every single stroke was the same length, the same pressure, the same little flick at the end. The whole passage looked like wallpaper. Dead surface, no air in it.

It got me thinking about how easy it is to fall into a mechanical rhythm with the brush, especially when I'm working alla prima and moving fast. The moments in my paintings I actually like tend to be the ones where the mark changed because the form demanded it, not because my wrist was on autopilot. A drag here, a loaded press there, a palette knife scrape when the brush was building up too much.

What has helped me a little is switching tools mid passage. Even just flipping to a filbert from a flat will interrupt the habit long enough to make me actually look at the shape I need. But I still catch myself falling back into the pattern, especially in foliage or water.

How do you keep your surfaces from going stale? Do you consciously vary your marks, or is there something else that pulls you out of the loop?