The right sunglasses never go out of style. But who hasn't been swayed by designer frames, or a duty free bargain, and ended up with shades that don't suit? The key to successful sunglasses shopping is to allow ample time, and to get a second opinion - it's hard to judge your reflection with shades on. Better still, get your shopping partner to take photos of you.

The right style for you will depend on your face shape, but think about  frame colour, too. Black can be harsh against some skintones, so if you're prone to looking washed out try tortoiseshell instead.

Finally, it's worth investing in your sunglasses, so skip the cheap and cheerful pairs in high street shops.  At best, these will give you 'nose dents', at worst they won't offer adequate UV protection. Here's how to pick the right pair for you.

Round face

If you have a baby face, with full cheeks and rounded chin, you're aiming to add definition and make your face look longer, rather than softer, or wider. Go for angular

If you're keen on clothes, you'll know that now is the most annoying time of year to get dressed. How can it be so sunny, yet still chilly. Suddenly, black opaque tights don't look right.  But unless bare legs aren't a realistic option (even if yours are presentable after a winter cocooned in jeans, it's too cold). In a few weeks you'll be fake tanning in earnest and nothing will look too wispy or summery.

In the meantime, you need some tide-over buys. Here are some options to see you through till spring really sets in.

Print trousers
I've tried them, and I can tell you it's a risk worth taking.  Do it now before they become ubiquitous and don't spend much — these are a fly-by trend. Try Zara, Mango or H&M and go for low slung, slightly tapered cuts (flattering on most body types).  Or, if you go for this season's wide legged pyjama shape.  Wear them to work with heels and a plain silk or jersey top, and female colleagues will coo.

Left: Olivia Palermo/Rex. Right: Trousers, £12.99 H&M.

We all know that 'size 10' can vary wildly in different shops. But until every brand cuts from the same template (never going to happen), a new online sizing programme may come to our rescue. What Size Am I, tells you what size will fit you best in different UK and US shops.

I enter my bust, waist and hip measurements and the site comes back with a list showing my top, skirt and dress size in various shops. Depressingly, it tells me my best fit on the high street is Monsoon.

As I suspected I'm a size eight at ASOS, Dorothy Perkins, Karen Millen, Monsoon, Oasis and Topshop but a size six at French Connection, Jaeger, LK Bennett, M&S, Next, New Look, Reiss, Warehouse, Whistles and Zara. At Gap and Banana Republic I'm a four (these two are sister shops).

I'm a fairly normal shape so it's surprising that I split the UK high street down the middle. I test out the site's suggestions in shops, and it's right every time, except in Gap where I prefer the look of size six to the site's

Forget The Artist vs The Help, this year the Oscar red carpet was divided into hot reds, frothy mint greens and virginal white gowns. And the winners for best red carpet trends are:

Scarlet womenEmma Stone, Michelle Williams, Natalie Portman and Jane Seymour © Rex Features

Matching the red carpet was the plan for Michelle Williams, Natalie Portman and Emma Stone. Far from blending in, these ladies in red nabbed headlines - Portman in her sweetly starry vintage Christian Dior, Michelle Williams looking just the right side of  bombshell in Louis Vuitton, and Emma Stone in a sweeping, scarlet gown by Giambattista Valli. Not forgetting the magnificent Jane Seymour in glittering, crimson. Fruity reds and pinks work for these occasions because they're attention grabbing, with no compromise on classic elegance.

[Related feature: Oscars 2012 the winners in pictures]

[Related feature: Oscars 2012 red carpet fashion]

Red carpet bridesCameron Diaz, Rooney Mara, Octavia Spencer and Milla Jovovich © Rex Features
What was it with all the white? Variations on wedding dresses were everywhere, from Cameron Diaz's glitzy, oyster coloured Gucci, to Octavia

You know those women who look like they shop on Bond Street, but when you ask where their jacket's from chirp: 'Zara!' They don't shop in a secret high street you don't know about. They just know which high street brands do what, well. Once you're armed with this knowledge you can save hours of shopping stress, by going straight to the good stuff in each shop. Goodbye ill fitting manmade fibres — hello fake designer wardrobe. Here's what to buy where:

Best for: Workwear

If you're office is quite formal head for Reiss and Hobbs — their skirts, jackets and trousers are all office appropriate without looking frumpy. If you work somewhere less conservative, but still want to look pulled together, your best bet is Cos. Their tailoring is spot on, inexpensive and they do excellent copies of catwalk dresses.

Photo: Hobbs London

Best for: Knitwear
Uni-qlo's cashmere and merino wool sweaters are the best on the high street, both for quality and sheer choice. They have every neckline and colour

Stuck in a shopping rut? Try these five style swaps.

Do you always return from shopping with more jeans and another Breton top?

Do you envy other people's clothes, but fear you couldn't carry them off? You're probably stuck in a style rut.

Overhaul your whole look starting with one tweak and you'll find the others will follow. Think how great it feels when you step out of your comfort zone, and try one thing you wouldn't usually next time you're shopping.

If you always wear: Jeans
Try: Leather trousers

Stay with us! Gap and H&M do leather trousers but they aren't the Bon Jovi midlife monstrosities you think. In fact, with a sheer blouse or metallic jumper, they're practically workwear. And if you're wedded to your skinnies, they're the perfect alternative - tomboy-sexy, casual but glamorous and ideal if your legs are your best bit.

If you want to splash out, J Brand's £289 Maria High Rise Coated Skinny is as flattering as its jeans. If not, try Topshop's Shiny Faux Leather Trousers,

Want to feel better dressed? Follow these 10 New Years fashion resolutions for 2012.

Pretty up in pastels

Bye bye brights, ice creamy pastels are back (see Louis Vuitton's spring collection). If you're worried about looking twee stick to sleek silhouettes, and anchor sugary shades with black tights. Go for warmer pinks if you have sallow skin, and cool blues and greens if you have warmer, pink toned skin. Most of us should leave pastel yellow well alone.

Lighten up

No walk in wardrobe? Next best thing is to light your cupboards properly. Either have your closet fitted with lights, or just angle a lamp so that you can easily see what's in there. A small change that will make a surprisingly big improvement.

Store my leopard print

It's all about bird and feather motifs now — so put your leopard print and snakeskin in storage. Check out Giles, Marc by Marc Jacobs and Mannish Arora for inspiration coming soon to a high street near you.

[See also: How to get your bra fitted