Descriptive:
* After the heavy rain, tiny rills of water snaked down the hillside.
* The spring melt created a network of rills across the snow-covered meadow.
* The rills in the clay soil were evidence of the recent downpour.
Figurative:
* Tears streamed down her face like rills of sorrow.
* The poet's words flowed like rills of inspiration.
* The artist's brushstrokes created rills of color on the canvas.
Scientific:
* The rills on Mars are thought to be evidence of past liquid water.
* Erosion by rills can significantly impact soil fertility.
* The study focused on the formation and evolution of rills in different geological settings.
Remember that "rill" is a noun, meaning a small stream or channel, especially one formed by running water.