With accents I usually stick with those I know, i.e. Cockney, Norfolk or Somerset.
Cockney is the most often used in my work. I usually pretend I'm down the pub with my brother-in-law and listening to him or his friends saying the dialogue.
However, even if you watch East Enders you'll notice that in addition to a bit of Cockney banter to keep the punters happy, the actors rarely miss a hard 't' sound - which Londoners do. I think the reason is that many viewers would find what the actors are saying impenetrable if they did, and the programmers don't want to lose their audience.
I do a similar thing. If a Cockney's talking, I'll miss out most 'h' sounds but make few other changes perculiar to a pronounced London accent.
As I recall, Thomas Hardy was good at projecting accents with his rustic characters.
For an example of over the top accents, try 'The Secret Garden' (Northern accents). Excellent story, but myself and my daughter gave up reading it.
So I think the rule is not to overdo an accent. Just have enough of it, if it's needed, to convey character.
DW
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