Brit crossword puzzles aren't so bad once you understand the rules. What I did was get a book of cryptic crosswords (as they're called here in the US) to learn the clues within the clues (they're listed in the first few pages) and now I can do them fairly well. I still prefer the NYT Sunday, though.

Alex, we have a friend who constructs crosswords. He was featured in a local paper a couple of weeks ago. In the article, he explains (sort of) how it's done. I'm trying to find the article on-line. Meanwhile, I bet a google of Will-Shortz will uncover something.