The first is my favourite illustrator of the moment Linn Olofsdotter. Her work is always intricate, beautiful, colourful and often surreal and strange. I originally found her on www.coolhunter.com . See more of her work at http://www.olofsdotter.com/
The second is an illustrator my Art director came across, Audrey kawasaki. She paints beautiful, almost art nouveau images of young girls which are often highly erotic yet still innocent, and sometimes melancholy. Eyes are narrowed as if the girls are thinking about their own images. Her images are painted on wood which perhaps lends them innocence. http://www.audrey-kawasaki.com/galleries.php?g=1.
The third artist was one I stumbled across after seeing a book cover for author David Mitchell which I admired. Their natural images are intricate and build patterns and often work within confined pallets - different shades of green, different shades of orange. Take a look here: