A friend sent this link around, and I can’t recommend it enough. Ten tips on writing a novel from some of the best contemporary novelists around. (also useful principles for any kind of writing really).

http://www.guardian.co.uk/books/2010/feb/20/ten-rules-for-writing-fiction-part-one/print

and

http://www.guardian.co.uk/books/2010/feb/20/10-rules-for-writing-fiction-part-two

The only one to add is this one, which is complete gold, from Ann Le Motte:

 “The only way I can get
anything written at all is to write really, really shitty first drafts. If one
of my characters wants to say ‘hey there Mr Poopy Pants’, then I let him.”