I realize this is now the third time I've linked to a style website that I don't really like, so I'll remedy that by sharing this link: http://permanentstyle.blogspot.com/

Written by a youngish guy in London, it's not kilt related but focuses on classic British style. The posts in the sidebar under the headings "Philosophy" and "The Rules and How to Break Them" are particularly good. As I said, it's not about kilt wearing at all, but I think many of the principles he talks about can be applied directly to putting together kilt outfits.