My absolute favourite form of light painting, and something I'd be doing this winter if the ground wasn't so waterlogged, is blue hour lightpainting in the landscape.
For this shot, taken in the Peak District, I waited until 40 mins or so after sunset and then used an acrylic rod attached to a coloured torch to draw this complex hand drawn design.
All the other illumination is just the natural afterglow of sunset over a 5 minute exposure or so.
For more of this stuff, check out @lightpaintersunited for some visual goodness