StyleSMALL PRINT: As in life, so in fashion: there are myriad rules about how one should dress, from colour to hemline to décolletage. However, as in life, these rules can be broken.

Colour combinations are, of course, the most common. Navy and black are thought of as a devilish pairing, but there’s nothing more chic than combining an indigo jean with a black blazer. Pink and red is another one – but with Matthew Williamson pairing the two for A/W 2011, it’s time for a revision. This is a fresh look at colour blocking and a sure way to get attention.

As for hemlines, we are told never to pair a low neckline with a short hem. Show off one, we’re told – not both. Blake Lively (right), however, has proven that one can be respected (being Karl Lagerfeld’s muse) and desired (take a look at her) while showing a cheeky amount of breast and leg.

Read Rosemary’s fashion blog, Fash Mob, at irishtimes.com/blogs