You will need to allow a couple of hours (depending on whether you already have a pared down wardrobe or whether it flows into other areas of your home like mine does!) and if you have a discerning and tactful friend to help you, that will be a bonus.
Of course, if you've been taking part in the 7 Steps to Style challenge, you will have your style recipe to refer to, as well as your lifestyle charts. You will also know what styles flatter your body shape and your best colours. This should make it easier when going through your wardrobe and sorting your clothes into piles. Imogen suggests the piles should be: clothes that you wear regularly; clothes that you either don't wear or haven't worn in the last couple of years; clothes that you haven't worn for a while and maybe only wear a couple of times a year. You might want to add a pile for clothes that you know should definitely be thrown out, either because they don't flatter you or because they are way past their best.
You now need to try on your clothes to decide whether you will keep them, making sure when you do so that you look good in them and that they are appropriate for your lifestyle. Did you last wear that suit when you were working in a formal office environment? Was that over five years ago? In which case, it's probably one to donate rather than to keep. Do you have several different black t-shirts, jumpers, cardigans and dresses but no longer wear any of them as black looks too harsh on you? They too should be discarded.
I have discovered over the last couple of years, as I have learnt more about what suits me and have started cutting back on my wardrobe, that I am wearing the majority of my clothes on a regular basis. I still have occasional lapses and impulse buy when the sales are on - and guess what? Most of the clothes that I hardly wear have been impulse buys.
Going through my wardrobe when I was creating the capsule of 33 items of clothing for my Winter 33, I realised that fifteen of the items were recent purchases or Christmas gifts, including those that I chose for myself with money my DH gave me. That's hardly surprising, as taking part in 7 Steps to Style has shown me which styles suit my H shape body and which colours flatter me the most. My recent purchases haven't been impulse buys: they have been informed purchases using knowledge gained through 7 Steps.
This photo shows me wearing today's outfit, which I'm happy to say the other members of the 7 Steps to Style facebook group approved of. The cardigan is what Imogen refers to as a "hero piece", as it's clearly the centre of attention. My necklace, top, trousers and shoes are all neutrals so they don't detract from my cardigan, and I chose brown as it is one of the colours in the cardigan.
When going through my wardrobe in January, there were a couple of items that I hesitated over. One was a red jumper that I decided to include in my Winter 33, however I doubt if it will make the cut next year as I've had it for a long time. The other was a pair of boot-cut jeans that are slightly faded: I'm going to see if I can dye them first and, if that's not successful, they will definitely have to go.
While going through your wardrobe you should be able to reduce it by rejecting those clothes that don't flatter you, aren't suitable for your current lifestyle, no longer fit you or frankly are beyond help. You may put some to one side to be revamped - in my case it was the boot-cut jeans and a cashmere cardigan that needs altering - or, if the clothes are in a good condition but no longer suit you, you could consider selling them on e-bay or take them to a charity shop/thrift store. My clothes go to the recycling bins to help a Spanish social action group "Proyecto Abraham".
Hopefully by the time you've gone through this process you will still have enough clothes to make a viable wardrobe. If not, take a note of clothes that have proven their worth but need replacing or any obvious gaps in your wardrobe. Don't go shopping yet though, as the next two steps are just as important!
Postscript: I sent some photos to Imogen showing different sections of my Enigmatic swatch, and she has replied advising me which colours she feels should be my signature colours. Here they are - what do you think?