Before you put the Christmas decorations back in the loft, try using the tree’s string lights to provide a soft, ‘bokeh’ backdrop to a close-up shot. The trick is to use a lens that focuses close, but which has a focal length that’s long enough to make the lights appear large in the frame.
For these shots, I opted for 100mm f/2.8 macro lens, but, depending on the size of your subject, you can achieve good results using anything from an 85mm lens to 70-200mm one.