How to remember
The kanji 石 depicts a cliff (厂) with a small stone (口) sitting at its base or falling from it. It visually represents a rock or stone. 'Seki' — Imagine 'SEEKING' a good STONE to skip across the water. The top part `厂` looks like a cliff or a overhang, and the bottom `口` can be seen as a small stone at its base, or the mouth of a cave in the rock.