Organising a couple's big day is no mean feat, but the stakes are much higher if your clients are royalty.However, Peter Phillips and Harriet Sperling's wedding planner, Peregrine Armstrong-Jones, is well-accustomed to the pressure, having masterminded some of the world's most high-profile nuptials.It was his world-renowned firm, Bentley's Entertainments, that organised David and Victoria Beckham's Irish extravaganza in 1999, Elton John's wedding to David Furnish in 2005 and Prince Albert of Monaco's ceremony, as well as the nuptials of both Princesses Beatrice and Eugenie to their husbands.But what does Peregrine, the half-brother of Princess Margaret's husband, Antony Armstrong-Jones, recommend when it comes to planning a big day?Thankfully, the 66-year-old previously shared his best-kept secrets in 2024, including serving 'common food' to his rule for having a 'packed' dance floor.The most important thing is to uphold the client's privacy, especially when a wedding is going to 'dominate the front pages', he explained.'Everybody has the right to a private party. We all agree that's how it should be,' he said.The biggest challenge is ensuring there are no leaks - from the guests to service providers like caterers and florists - during the planning and execution process.One of the ways Peregrine and his 'secret weapon' wife, Caroline, do this at Bentley's is by placing all orders in the name of the company, rather than the bride and groom. Peregrine Armstrong-Jones is planning Peter Phillips and Harriet Sperling's Cotswolds wedding tomorrow Since launching in 1985, Bentley's Entertainments has earned a 'client list that encompasses royalty, Hollywood A-listers and respected professionals from all over the world', according to the website. The decision to ask Peregrine to plan Peter and Harriet's wedding was likely a no-brainer; not only was he responsible for the royal groom's first wedding to Autumn Kelly, but his events company also pulled off Zara Tindall and Mike Tindall's 2011 nuptials at the historic Canongate Kirk in Edinburgh, Scotland. Peregrine and Caroline have previously organised A-list parties and royal weddings everywhere from Mustique Island and St Barts to Moscow, but their next assignment is much closer home. On Saturday, Princess Anne's son will tie the knot with Harriet in Kemble, a civil parish in the heart of Gloucestershire. The pair will say 'I do' at All Saints Church, an Anglican parish church that is said to date back to the 11th century.Following the private ceremony, guests will toast to the happy couple at a reception hosted by the groom's family at Princess Anne's Gatcombe Park.While most couples don't have access to a royal residence for their big day, Peregrine's wife Caroline said her best advice for brides and grooms-to-be is to 'go somewhere you have as many resources as possible included in the per-head' cost in an interview with Hello! magazine. 'For instance, hotels have their own chairs, tables, linen, china and glass – that’s a big cost when you’re setting up in a venue that has nothing. Hotels have their own kitchens,' she said. According to Peregrine and Caroline, the success of a big wedding comes down to the little details - from having a varied menu to the choice of china and flowers. Party planner to the stars pictured at Zara and Mike Tindall's wedding at Canongate Kirk in Edinburgh on July 30, 2011 When it comes to the food, Peregrine said he subscribes to celebrity chef Rick Stein's philosophy: 'Cook common food uncommonly well.' The celebrity wedding planner also revealed how 'lighting controls the mood and atmosphere' at weddings and the secret to having a 'packed dance floor'. 'Whether you have a DJ or a band, they need to be playing music that your guests know – no B-sides and nothing but hits. After all, you want a packed dancefloor,' Peregrine said at the time. While details of Peter and Harriet's 'intimate' royal wedding have largely been kept under wraps, new photos from Gloucestershire this morning showed how their wedding venue was being transformed with white, pink, and blue flowers. Pictures showed members of Bentley's team assembling a mixture of foxgloves, Canterbury bells, lupins, delphiniums and a selection of English roses, while police officers secured the perimeter around the All Saints Church in Kemble, which dates back to the 11th century.These images suggest that the couple may be opting for a more minimalist and all-foliage wedding, with a focus on greenery rather than traditional flowers, as trucks full of large, verdant plants were seen arriving at the venue.Crew members were spotted carrying large urns and decorations yesterday into the church in Kemble, the sleepy Cotswolds village set to host the toast of high society and the royal family.Among those expected to attend are the King and Queen, alongside Peter's mother Princess Anne and her husband, Vice Admiral Sir Timothy Laurence.However, it will be a busy day for Charles, 77, who is double-booked and expected to attend Derby Day at Epsom after the ceremony.Also expected at the ceremony are the Prince and Princess of Wales, as well as the Duke and Duchess of Edinburgh.However, Peter's cousin Prince Harry – who lives in Montecito, California, with his wife Meghan – will be notably absent.A friend close to the Princess Royal's son said: 'Peter and Harry haven’t spoken for several years and have simply lost touch, so he hasn’t been invited.''Peter and Harriet's wedding is an intimate occasion with their close friends and immediate family around them in the Cotswolds. It’s an area where they grew up and is very special to them both,' a pal said.Peter's sister Zara and her husband Mike will also be present at the celebrations, along with the daughters of disgraced former prince Andrew, Princesses Beatrice and Eugenie.