I always like to take discreet pictures with them while they perform their duties, because they look simply perfect in their traditional clothes, with the white haori (the kimono jacket) - white symbolizes purity - and the vermilion hakama. Actually, I once dressed myself in such a costume and I loved it!
And speaking of costumes, the cutest miko attire I saw is the one from the Kasuga Taisha Shrine from Nara - the miko usually wear red or white hair ribbons, but here at Kasuga Taisha they have this unique hair ornament, like a horn in the middle of the forehead:
EXIF info:
Nikon D90
Lens: VR 18-55mm F/3.5-5.6G
Focal Length: 18mm
Aperture: F/5.6
Shutter Speed: 1/160s
ISO Sensitivity: ISO 200