(Jacket by Christopher Kane, trousers by Joseph, t-shirt by Zoe Tees, shoes by Camilla Skovgaard, sunglasses by Tom Ford)

It can cost you a fortune and make you terribly grumpy. ELLE fashion features director Rebecca Lowthorpe provoked a bout of envy in me last week when she turned up at ELLE towers in a Céline coat so covetable I contemplated stealing it and blaming it on my PA. I’m pretty sure Alexa Chung was wearing it, too, when I sat next to her at the ballet last week.

I had a classic case of ‘the one-piece syndrome’ jealousy, too: where you know that if you pick the right investment buy at the beginning of the season, your getting-dressed worries will be taken care of until the next season. That three-quarter-length Céline coat is Rebecca’s ‘one piece’ – her whole wardrobe has been built around it and it works perfectly.

I’ve yet to purchase the one piece that makes everything else work, so I’m in fashion limbo, desperate to make a decision and jealous of those who have already got their outfits sorted. Which is why I road-tested this exquisite jacket today. I love it but is it the one piece? I’m not sure.

To help me make up my mind, I asked Rebecca why she chose her Céline coat. She said, ‘I had this idea of how I wanted to dress: dead simple, stripped back, a bit boyish. So when I first saw the coat in Dover Street Market I fell in love with it, but it was too small.

‘Still, the coat inspired such a strong idea of how I wanted to look that I proceeded to buy a whole wardrobe to go with it, even though I didn’t own it! Then, one day, I went to Matches and saw my Céline coat in my size. Since I’d already bought the pieces to go with it, I really would have been mad not to buy it.

‘I don’t regret spending so much on one item as I know it will last a long, long time and I know every time I put it on, I feel great. Everyone always asks what I’m wearing, too; it’s the compliment coat.’

(Rebecca Lowthorpe wearing her Céline coat at fashion week)

Now, while I know this Christopher Kane jacket is going to receive compliments, I wonder if it has a better partner than me waiting for it? I wore it for a meeting with the charity The Halo Trust, of which I am a newly recruited trustee, and the jacket was too attention-seeking for its own good. However, at a meeting at EMI records, it found itself more at home. Therefore, I think I’m still looking for my one piece.

If you want a statement jacket this season, I suggest choosing a ‘big noise’ jacket in a colour that suits you and dressing everything else down so it stands out. and have some great jackets, or there’s embellished denim at Ashish. For a good shape, and are favourites of mine, but if you need a more classic suit jacket try Joseph for long-term buys.

This season, many designers have offered a twist on the traditional jacket shapes with cut-out and embellished details. For example, a black tulle biker jacket at , a biker vest overlaid with chiffon at , a jewel-encrusted bomber jacket at , sequin-covered jackets at and origami-like cuts and folds at .

The trends most seen on the high street, meanwhile, are coloured and patterned jackets, printed bomber jackets, neon denim biker jackets and sports-inspired parkas. Functional, practical styles are given a makeover this season. I like River Island’s pretty, embellished coats and jackets, the embellished-leather pieces at All Saints, Zara’s twist on tweed and ladylike jackets, and the leather and tailoring at Reiss. Just don’t go for black – it’s boring!

Here's the back of Fashion East designer Maarten van der Horst's jacket. I'm road testing one tomorrow so we'll see if it's 'the one'.

And the front. See we think of everything.

Athé is the difussion label of Vanessa Bruno and this is a great jacket or spring coat. I've bought the trousers that match.

This Flirty bag is my new best friend. We are in love.

Here she is again just in case you didn’t appreciate her the first time.

TODAY THE EDITOR:

Is Reading Capital by John Lanchester

Is Listening to A Real Hero by College.