Forget musty, cramped shops and clothes rails jammed with tired, high street cast-offs; the new brand of posh charity shops are clean, stylish and full of barely-worn, cut-price designer goodies. With the notoriously changeable fashion world waking up to sustainability, pre-loved clothes are the coolest way to shop. Stylish British televeision presenter Miquita Oliver, a long-time charity shop devotee, buys good quality tailored menswear and has it altered to fit at her local dry cleaners. She recommends focusing on a specific goal - denim, cashmere, evening wear - and then picking your location to suit, thinking about what the residents wear and are likely to donate. For example, Marylebone High Street, King's Road and Belsize Park are good for classic designer labels. Alternatively, if you are more Noel Fielding than Noel Coward, head to Hackney or Dalston. Either way, we've narrowed it down for you. Get in first and nab those early-bird designer bargains with this rundown of our favourite posh charity shops in London. Save the Children: Mary's Living & Giving Retail and brand communication guru Mary Portas shook up the concept of charity shops when she reimagined them as premium retail stores. The prices may be a little higher than average but the vibe is very much like shopping in any other retail clothes store. Merchandise is top quality and professionally displayed - and your fashion spend is literally saving children's lives. There are branches throughout London but our favourites for designer finds are Bermondsey, Blackheath and Primrose Hill, with a special mention for Portobello Road; apparently Vivienne Westwood donates items there regularly. Website Fara: Retromania, Pimlico Any vintage or retro clothing donated to Fara shops gets rerouted here. It is a vintage Aladdin's cave with some iconic designer pieces in the mix, so expect to be jostling for bargains with London's beautiful people. A huge selection and a pretty rapid turnover, it's worth regular visits to see what's new. Profits go towards Fara's programmes in Romania. Website British Red Cross The British Red Cross have specialist designer and vintage boutiques in Kensington & Chelsea and Portobello Road. Unsurprisingly, given the areas, the donations are high quality; don't be surprised to find clothes with the original tags attached. The charity also partner with Zara, who pass on all clothing that is donated in-store. Give your wardrobe a swish, stylish and wallet-friendly upgrade, while helping people in crisis in the UK and across the world. Website Shelter: Boutique at Coal Drops Yard Boutique by Shelter is possibly the poshest of our posh charity shops; even the interior is bespoke. This flagship store is as close to a hip high street shopping experience as you can get. Browse through the carefully-selected designer, vintage and quality high street clothing, pick out some cut-price classics and know that your purchases are helping to prevent homelessness. Website Oxfam Boutiques in King's Road Chelsea and Westbourne Grove have the cream of the designer crop but check out the Notting Hill, Dalston and Marylebone branches too. As one of the big-name charities they get a lot of donations, so stock turnover is high. A stylist's tip that works for all of our shops is - girls, don't forget to browse the men's clothing section. There are some gorgeous tailored jackets and shirts hiding on those rails. https://www.oxfam.org.uk/shops/?query=london Traid Traid is all about reducing the environmental and social impact of the clothing cycle, so has absolutely nailed reusing pre-loved clothing. We love the finds at Dalston, Peckham and Westbourne Grove but (as with all our suggestions) please don't stop there. Get into the habit of stopping by your local shops, find a favourite and get to know the staff; you may find they will put items aside for you if you are a regular. Website British Heart Foundation, Balham Great for those luxe high street brands more than full-on designer labels, here is where you go to build your capsule wardrobe of classics. Pick up the ultimate LBD or tailored blazer and fund vital medical research as you shop. Website Lama's Pyjamas, Bethnal Green A much-loved destination on Roman Road, this is the place to go for designer labels at bargain basement prices - and one of the most chilled retail experiences you'll ever have. It's usually possible to pick up a whole new outfit for under £25. Proceeds go to the London Buddhist Centre, funding classes in yoga, meditation and mindfulness to combat stress. Website To show how far removed today's posh charity shops are from the old-school style, many have Depop and eBay sites; worth knowing if you prefer shopping in your PJs from the couch. Head to their websites for links and get a little good karma with your next outfit.