i did luxord at nakakon last year. i used a light brown eyebrow pencil to color on the goatee, then used a bit of my own hair finely chopped up and spirit gummed it on over the pencil. other than being extremely light blonde, it looked realistic enough that my friends didn't recognize me in the hallway and everyone who sees the photos thinks i'm a guy
it's itchy and a pain to get the spirit gum off (make sure you have remover) but i think it's worth the discomfort
http://www.cosplay.com/photo/3209863/