Whenever magic would help, you have to use it and damn the consequences. Running low on power (glamour, mana, etc.), attracting attention, suffering a token's backlash, etc. are all irrelevant if the effect of the magic would improve things for you.
Roll Resolve + Composure to suppress the urge to solve your problems with magic.
Examples: using contracts or tokens to solve a mundane problem, traveling through the hedge for your daily commute, or spending glamour on a Persuasion roll when angling for a discount at the grocer.
Mundane characters can gain this derangement as long as they truly believe they are able to perform magic.