There are posters on the Underground which say that people should always
swipe in and out so as to get the best fare.
If by 'best' they mean cheapest they are wrong.
Surely if you have the chance you should either not swipe in or swipe out,
or both.

--
Work like the ponies in coalmines.
Dance like the teardrop explodes.
Love like you're Frank in Blue Velvet.
Sing as though your little throat would burst.