What I want is how best to travel from Tottenham Hale to Camden Town?

Simple question?
snip
Then use what I call the stairs short cut (right by the front of the
train on arrival at Euston) to the bank Branch of the Northern Line.
Northenr Line to Camden Town

The reverse is similar. Always get a Bank Branch train from camden
Town. Sit in the rear most carriage and then at Euston use the short
cut stairs (right by the rear carriage) to the Victoria Line
Northbound.

This saves having to go up to "high level" (which you end up doing if
you use a charing cross train) and then down again at Euston.

That's handy, that. On a slightly different note, am I right in thinking
that it's a cross-platform interchange for Southbound Victoria/Southbound
Bank Branch, and the same for Northbound?

--
"For want of the price of tea and a slice, the old man died."