Requires little equipment and is generally more fun and involving than the real thing.

Play your own Scattergories

Apparently this is a well known thing in the military, but no one told me until we learned about it in the film Beneath Hill 60. But I think the primary use case is going for a pee in the night.

Shut one eye to keep your night vision

I figured this out while trying to draw one. The epiphany was noticing that the s-line in the centre is uninterrupted but part of two chain links. Neat.

Draw a chain