Subtle understated, simple hair and makeup. Think functional and tidy.
Not bling - classy, simple, elegant - plain watch, bangle if you must simple necklace and earrings. Like pearl, plain gold or silver.
Heels, not too high and not too evening.
I'd go plain black dress or skirt and jacket with a white shirt - you can always wear a coloured scarf if you must. Or coloured handbag.
But I tend to wear what would be called boring, plain, conservative clothes to interviews. Plenty of time to introduce your own personality into your wardrobe AFTER you get the job. I want them focusing on my replies, and remembering ME, not the hot pink heels I wore.
ETA - 30+? No jacket - white shirt and black skirt and low black heels would be my pick, or a navy, black or tan shiftdress.
Edited by lynnemine, 16 November 2012 - 03:58 PM.