I managed to get these shots by resting my camera on a chair to steady it (no tripod in this house!) and then turning the flash off. These are much truer to the actual feel and warmth of the tree and the room.
But, patience is a virtue and today Ali Edwards posted a link to this blog which had a tutorial for getting bokeh style Christmas tree shots. We've had a busy day in London today so I'm too worn out to play too much but already I managed this shot of my magic lights, which I'm pretty pleased with.