What I want is to avoid classic belters like the one in Louise Bagshawe's Passion - the hero is in the process of rescuing the heroine from Bad Guys and hauls her into a tube station to make their getaway. Whereupon he pulls out one Oystercard and swipes it twice.
Which doesn't work and would have the revenue men up his arse like a rocket. Bagshawe obviously is too rich to use the underground, and too famous to be copy-edited, because that did make it into the published edition.
Having comitted sins of my own in the past (book of mine written in the 90s contains about a page describing the heroine's undertaking of the complex task of Sending An E-mail. And gets it fairly wrong, too.)
Anyway, what I want to know at the moment is: if you have no power in your home because the electricity is off, will your phone still ring? I can't test this myself as my phone is cordless so is dependent on having power to charge the handset up.