TECHNICALLY, autumn doesn't start for another couple of weeks, but if you're going by the sartorial calendar then it's well and truly here already.

The summer collections have long since been cleared from shop floors and the first drops of the new season have arrived, with snuggly sweaters and big leather boots making the prospect of dipping temperatures not quite so depressing after all.

There's lots to be excited about on the fashion front for autumn/winter, because the catwalks gave us some stunning - and, for once, wearable - trends, and now you can shop them to your heart's content on the high street. But don't, whatever you do, start spending until you're up to speed with the season's style forecast. Here are the seven key fashion themes you need to know about for AW18 and how to shop them now...

SEVENTIES

The decade most designers plundered this season? It was without doubt the Seventies, specifically the collars, coats and colours.

Collars were long and sharp at Louis Vuitton and Chloe. Coats were big and fluffy (Vuitton again) or suede at Tory Burch and Coach. The colours - brown, beige, mustard, chestnut - were everywhere, particularly the cosy layers at Roksanda and Miu Miu.

Try the trend: Miss Selfridge rust brown corduroy baker boy hat, £12; teddy coat, £65; rust tile v-neck pinafore dress, £28; stripe wide neck ruffle tee, £20 (shoes, stylist's own; coat and tee available later in September)

HEADGEAR

Hoods, balaclavas, berets, head scarves - all manner of millinery appeared in the AW18 collections. There were even crowns and tiaras at Dolce & Gabbana (there's the royal influence again), but if you're looking for something a bit less ostentatious, try a Versace inspired beret or floral head scarf instead.

Try the trend: TK Maxx Euroseta fashion black & purple silk floral scarf, £16.99

ANIMAL PRINT

If you've taken even a cursory glance at the high street of late, it can't have escaped your notice that animal prints are everywhere.

That's because leopard roared back into fashion on the catwalks, seen everywhere from Max Mara to Tom Ford, while zebra was trotted out at Balenciaga and Halpern, and tiger print growled on the girls at Bottega Veneta.

Try the trend: Dorothy Perkins beige brushed leopard print V-neck jumper, currently reduced to £22.50 from £30

LEATHER

An overarching theme of 'clothes as armour' emerged from the shows, and leather played a big part in that. The leather dress is one of the key pieces of the season, therefore, as seen at Stella McCartney (rouched), Givenchy (belted) and Victoria Beckham (collared).

Try the trend: Sosandar navy zip through leather look collared dress, £69

TWEED

A tweed transformation took place throughout the season, the traditional fabric given a modern spin by designers. At Altuzarra, that meant sharp overcoats while at Prada it was bright hues, but the most creative example was in London, where Matty Bovan showed deconstructed woven skirt suits with fabulous houndstooth boots.

Try the trend: Glamorous.com multi tweed button front blazer, £42

PLEATS

A knee-length pleated skirt has become a summer staple in recent years, but now designers are making the case for wearing a longer length in winter.

From the elegant evening styles at Emilia Wickstead and Lanvin, to the cream creations at JW Anderson and Victoria Beckham, the one thing they all have in common is that they're delightfully swishy.

Try the trend: Topshop pleated crepe skirt, £69

THE QUEEN

The Duchesses of Cambridge and Sussex may get the lion's share of the fashion column inches, but on the AW18 catwalks, the Queen was the undisputed style icon.

The most literal interpretation was at Toga, where Her Majesty doppelgangers, complete with gloves and head scarves, appeared on the runway. Regal silks and florals also made an appearance at Celine, Moschino, Richard Quinn and more, while the Town and Country tweeds trend also referenced the royal family.

Try the trend: lipsy floral high neck blouse, £34, Next