因故

因 = 囗 + 大 : Mnemonic symbol: the close reasoner René Descartes.

因 = 囗 + 大 : In front of the encampment, René Descartes, Maud Younger and a robot a starting a big rave. The robot sits inside a big box and is the master of ceremony, while René and Maud are dancing on the square. They started this rave to collect money for a good cause.

故 = 古 + 攵 : Mnemonic symbol: This character only appears in 做, so we don't need a strong mnemonic symbol. We should be able to refer to 故 when we think of 故事 or 故意. Because it fits nicely to its components, I'll think of it as in the meaning of 故墓, an old grave.

故 = 古 + 攵 : There is an ancient cloister in the space station's bathroom, and Gitta Giraffe once heard a story from her fellow astronauts that there's an old tomb inside with lots of treasure. One day she can't hold herself back anymore and deliberately breaks the cloister open using a sledgehammer.