In terms of accessories, Kate likes to spice up an outfit with a statement hat, usually from her favourite milliner Jane Taylor.
Cressida appears to favour simple headgear to hats or fascinators, often accessorising her looks with floral headbands.
With many comparisons being made to tomboy model Cara Delevingne, Cressida champions an off-duty look of black skinny jeans, tshirts, bomber jackets and sneakers or biker boots.
Kate, meanwhile, favours a more polished look of navy skinny jeans, Breton stripe tops, blazers and wedges.
Evening wear is also a different affair for each lady. Cressida was spotted sporting a multi-coloured silk jumpsuit and red platform wedges for 2011's Ralph Lauren Wimbledon party, while Kate sticks to floor-length ball gowns in block, muted colours – usually by designers Jenny Packham or Alexander McQueen — and simple stiletto heels.
Cressida was snapped enjoying herself at Glastonbury festival last summer wearing distressed dungarees over a slouchy white tank top. She teamed the pared-down outfit with green-rimmed sunglasses, a half-up top-knot and white hi-tops.
It was a far cry from the pretty, feminine dresses that Kate wears to the polo.
For more formal occasions, Cressida sticks to a boho, Sienna Miller-esque feel. For the wedding of Lady Melissa Percy and Thomas van Straubenzee last June, the 24-year-old teamed a flowing maxidress with a sequinned jacket and sparkly silver heels.
Kate's wedding style is more formal and structured. She tends to favour dresses with matching coat jackets and statement hats.
For another wedding in 2013, the nuptials of Rupert Finch and Lady Natasha Rufus, Cressida opted for the same maxidress/jacket formula, spicing the look up with the gown's floral pattern and fun pink platforms.
In 2011, Kate accompanied her husband Prince William to the wedding of the Queen's granddaughter Zara Phillips and England rugby player Mike Tindall sporting a very similar outfit. She had, however, chose to top the outfit with an oversized, disc-shaped hat that turned heads.