If it helps anyone, this was the sleep clinic approach we used which improved our sleep problems dramatically (C&P from a previous sleep deprivation thread)
This is taken from a Health Visitor article, called 'Peace at last: a model of sleep management for parents'
"The key to helping the child learn these new sleep associated behaviours is for the parent to provide support, but not attention. The parent should be advised to follow the normal bedtime routine, then at the very end, kiss the child goodnight and promise to 'come back in a minute to give a kiss'. However, they should actually return in seconds. They should move just a little and then give another kiss, then a little more, then another kiss, then occupy themselves - e.g putting away some clothes in the drawer - and give another kiss.
Then out and back for another kiss, and so on. The contract is: in bed, head on pillow, then a goodnight kiss, but no more chatter, no more cuddles, no more stories, play or drinks; just kisses until the child is asleep.
This may take 300 kisses and three hours on the first night, but it should be slightly less on the second night, then less on the third and fourth nights. Watch out for the fifth night, this is often the test night and may be as bad as the first. Once past the 'test night' by the sixth and seventh nights the new learning is usually secured."
We are using this routine for initial getting off to sleep and for night wakings - the advice we were given was to only leave 30seconds/1 min if leaving the room and returning at regular intervals.