7 timeless style lessons we learnt from the High Priestesses of fashion, Trinny and Susannah.

Image: Getty

Some people are born with an intrinsic, unwavering sense of style. Alexa Chung, for example.

Others, well… we have to learn it.

Like me.

Growing up, I was all 'peddle pushers' (three quarter pants), boob tubes, cotton skivvies and a really pretty purple velvet matching tracksuit. It would appear the part of my brain reserved for 'dressing like a functional human being' never quite developed.

Enter: Trinny and Susannah. You see, I didn't need subtle hints. I needed someone to grab me by the f**king boobs and say "BIG BREASTED WOMEN SHOULD NEVER WEAR HORIZONTAL STRIPES". And that is what these two well meaning, albeit slightly ruthless, agony aunts did. And I will be forever indebted.

So, at a time when I've never felt more like whipping out my purple velvet tracksuit (it's winter and jeans are itchy), I present to you the most invaluable lessons espoused by Trinny and Susannah.

Watch: Mia Freedman on learning she'd been wearing the wrong bra size her whole life. (Post continues after video.)

1. Buy a goddamn bra that fits.

I don't know if they invented this word, but every time I put my boobies in a bra I think "HOIK".

Hoik 'em up. Hoik 'em.

Nothing can ruin an outfit like a pair of badly-placed boobs.

Apparently 93 per cent of women are wearing the wrong sized bra. To demonstrate their point, Trinny and Susannah used to put their heads through the back of someone's bra.

Note: If your bra fits, you shouldn't be able to stick a human head through the back.

The biggest mistake women make is choosing a bra that is too loose at the back and too small in the front. In Susannah's words, a sh*tty bra makes your "jugs look like two pints of beer with froth spilling out the top."

If the back of your bra is riding up throughout the day, THROW IT IN THE BIN. It doesn't fit.

If you're a big breasted lady, wear a scoop or v-neckline, and avoid a polo neck. Always buy a bra with a wider strap, and two or three rows of hooks. Hoisting up the boobies will mean flattening the tummy and accentuating the waist. And there is nothing Trinny and Susannah love more than a defined waist.

If you're a small breasted woman, congratulations. You can wear just about anything.

2. The importance of proportion.

The duo famously proclaims that "in each case, it is proportion, not size, that matters."

In their book The Body Shape Bible, they argue the same principles of dressing apply to every woman, whether she be a Skittle, Cello, Apple or Pear (mmm... Skittles). Clothes that are well fitted allow us to re-proportion.

For example, I am top-heavy and have absolutely no semblance of a bum. Trinny and Susannah's solution? Never wear a white top and black jeans... or else I will look like a giant walking boob. Having done this multiple times in the past, I can definitively confirm white shirts make me look like a boob with arms and legs. Thanks, guys!

3. Always enhance the waist.

Nothing excites Trinny and Susannah more than discovering a woman dressed in a garbage sack is hiding a magnificent waist.

By cinching in at the waist, whether with a belt or a fitted dress, women accentuate their smallest point and look like they know what the hell they're doing.

4. Mid-calf leggings are the devil.

While we're on the subject of cinching in at our smallest point, mid-calf fashion leggings all need to be thrown into a pit and burned. And then buried.

I say 'fashion leggings' because gym wear is a completely different story.

Mid-calf leggings cut off on one of the widest points on a woman's leg, which makes them look bigger than they are. Screw losing weight, just wear tights that go all the way to the ankle.

An additional leggings tip: Wear shoes that are the same colour as your tights, and you will create the illusion of longer legs.

5. Know your body shape.

As much as I'd love to dress like Elle McPherson, one of the Olsen twins or Beyonce, unfortunately I can't. Because if I do, I will look like a crazy person.

"The problem is that women try to dress like celebrities whose shape they just don't have. When you emulate someone else's dress sense with a different body shape it just doesn't work," Trinny and Susannah explain.

The duo never focuses on weight; they don't tell a size 16 woman to come back when she's lost a few dress sizes. In their words, "We would never f**king do that. Because she is the size she is." AMEN.

In sum, "Forget your size and discover your shape." Excuse me while I get that tattooed on my forehead.

Once you discover your shape, the heavens will open up and shower you with clothes that don't make you look stupid.

6. A word on jeans.

Choose jeans that suit you, rather than the ones that are in fashion.

7. Black is not always slimming.

"Whhhhaaaattt!?" I hear you yell.

Well you, my friend, must have missed the episode where Trinny and Susannah staged a very scientific experiment that involved different coloured boxes.

They had passers-by examine a number of boxes, all different colours, and assess which they thought looked the heaviest. And guess which box won? The black one.

Susannah says “For us black is such a heavy colour. It weighs you down and just makes you look like a blob." (Post continues after gallery.)

In fact, most people look more svelte when they colour block.

Just in case your mind wasn't blown enough, Trinny also insists only HALF OF ALL PEOPLE suit the colour black. She says the key to colour is choosing "the right tone to match your skin, hair and eyes."

So, on behalf of all of us born without any sense of style, we thank you, Trinny and Susannah.

What's the best style tip you've ever heard? Tell us in the comments!