So it seems that at both Green Park and at Bank not following the
signed instructions is the way to go! There's obviously a number of
routes between lines at interchanges, but I'm just trying to think if
any of them are as essential as these two for the savvy subterranean
traveller. (In general I reckon it's a bit out of order to go the
wrong way down a one way tunnel, but that said when you're in a rush
to get the last train I think one can be forgiven for abandoning such
niceties).


Yep, I go both ways home depending on how I'm feeling and what's working
or not. The secret to the Bank interchange is indeed to follow the
Northern line route and then dive off.
At Bond Street you need to find the passageway on the right hand side of
the Central Line escalators as you go down. It's not currently signed as
an *entrance* to the Central line and at the platform is not signed as
an exit either (except for emergency purposes). So practically nobody
uses this passageway and you can get ahead of quite a few fellow
commuters. Sneaky huh?
Mark.