Let's assume for a moment that, like me, you have peered under the lid of the dressing up box that bears the label "Autumn Winter 2011 trends", stuffed, as it is, with 1950s, 60s and 70s retro looks, with lashings of fetish and cross-dressing gear thrown in. You like what you see, but you have sensibly decided that while it might work for a fantasy version of your life, in which you would teeter to a cab in 140mm heels, a sleek up-do and a mink stole, it won't work for the life you actually live, which involves trains, meetings, school gates and actual walking.

So, instead of the dressing up box, you want to make some great autumn buys which will be versatile, practical and extend your existing wardrobe, while at the same time signalling to the world (or at least, your slightly more on-trend girlfriend) that you are totally across all the key looks for autumn.

The first item on any list of key purchases is a coat. Our main coat edit will appear in two weeks but the two shown here make it on to our "key buys" list by fulfilling three vital criteria: being a style statement; able to keep you warm and also able to work with all the different lengths around this season.

There is a deeply desirable black faux fur baby (£120, M&S), which cleverly gets over the length issue by hitting mid-thigh; and a three-quarter length cape coat in coral by Helene Berman which similarly gets round the length issue as well as ticking the "colour" trend box (though if coral feels too much of a statement, it is also available in camel).

You cannot have missed the fact that an on-the-knee or over-the-knee pencil skirt is the key buy for autumn. The truth is, a pencil skirt - without benefit of vertiginous fetish boots/shoes - can be a tad dull, so if you buy one in leather you not only avoid that risk, but also elevate a skirt into a wardrobe superstar.

You will have no trouble finding one, from the Balenciaga (£815 at Matches), to the M&S one, (right, £99), to the drop-dead-fabulous gold one at River Island

A leather skirt works best paired with a wool, tweed or boucle (but never leather) jacket, like the riding jacket or the boucle biker, both at Browns. .

If a leather jacket is on your to-buy list - and a well-cut one repays its outlay many times over by being both work and weekend-friendly - pair it with a wool skirt in the new curvier shape, like the grey one from H&M, pictured, or their overblown floral print version or a tobacco, unpressed pleat one at River Island.

If you don't want to buy pencil skirt in leather, visible zips definitely ramp up the glamour quotient. Particularly desirable is Diane von Furstenberg's knee-length skirt, with waist-to-hem zips at each side (£230, net-a-porter.com). Alternatively, choose a pencil skirt in one of the season's hot colours: red, burgundy, teal or mustard.

Despite their adorable simplicity, dresses are slowly being displaced by skirts and tops. But if you hanker for one, keep it simple and ensure it works under your jackets.

A ladylike blouse should definitely feature on your shopping list. While being slightly retro, it won't look like fancy dress and teams perfectly with a leather skirt. Fenwick W1 has a deliciously pretty one in nude by Schumacher (£219), while House of Fraser has an animal print one with pussy bow at £150 and Warehouse has a snakeskin print at £45.

If you prefer something sleeker, Zara has crepe ones with zips on the shoulder which perfectly elevate a simple pencil skirt, while Isabel Marant has a shell top in a hazy, feather print that will do the same (£295 at Matches).

By the time winter proper arrives, that wardrobe staple of the 60s, 70s and 80s, the polo-neck jumper, is set for a comeback. Unsurprising really, since a polo-neck not only looks brilliant with a leather pencil skirt, opaques and ankle boots, but will keep you warm. Some of the best are at Reiss, where they have leg-o-mutton sleeves, transforming them into a statement top half. You could also pair one with a pair of leather trousers, which also figure on the "hot" list. Look for them at M&S (£99), and by Mint Velvet (£199 at John Lewis).

When it comes to accessories, the hot new shade is tan. Glossy and neutral, it matches virtually every autumn hue and means that in these recessionary times, you can buy one pair of boots and/or shoes and one bag, and they will match almost everything you own.

As well as comfy-ish kitten heels, there are still ballerinas around (some have even grown a hint of heel), but the most on-trend flats are brogues and low-cut loafers. For boots, look for mid-heels or wedges, and buy ankle-length if you want them to go with that leather skirt.