Adjustable wrench use, how to quickly determine which way to turn the wheel
&lt; frivolous >

You have really already provided your own answer to this question. 

Up to widen the jaws.

As a mind joggler just remember "Up to widen your horizons".

Although this is useless if you flip the tool over.

&lt; /frivolous > 

If this is truly an issue why not paint, with red finger nail polish on each side, a turn direction arrow for the wheel and a corresponding one for the jaw direction.