The last items of clothing I added to my wardrobe were my summer suits, ordered months ago from Anderson & Sheppard, who have been making my suits for 20 years. I’ve got four for this season, among them a linen one in teal blue. As I mature, I get more wild – they used to always be navy blue. 32 Old Burlington Street, London W1 (020-7734 1420; anderson-sheppard.co.uk).

My personal style signifier is my Vacheron Constantin Toledo watch. It has an art deco feel to it – that’s one of my favourite periods, which is why I love it so. My mother and my partner, David Gill, gave it to me 12 years ago. It’s in gold and I customised it with a red strap. 37 Old Bond Street, London W1 (020-7578 9500; vacheronconstantin.com).

Sultana’s Vacheron Constantin Toledo watch | Image: Chris Floyd

The last thing I bought and loved was an Untitled portrait created this year by the Spanish artist Secundino Hernández, from the Victoria Miro gallery. David and I are big art collectors. It’s a surreal portrait, in shades of blue and grey: I was immediately struck by it. All his work is incredibly strong – both the colour and the composition. 16 Wharf Road, London N1 (020-7336 8109; victoria-miro.com).

The thing I’m eyeing next is a kitchen by Plain English. I have never had a proper kitchen where you can cook, eat and hang out in the same space. I’m renovating an apartment in the Albany, where we live – this one has not been touched since 1959 and doesn’t even have central heating. It’s a tough project, as I need to blend the Georgian architecture and its past with my own style, which is more contemporary – it’s really testing my boundaries. plainenglishdesign.co.uk.

The last meal that truly impressed me was at The Harbour Club in Valletta. It’s one of the most atmospheric restaurants in the world. An outside terrace decorated with twinkling lights looks over the Grand Harbour onto the boats moored below. My favourite dish was the wild boar lasagne. 4/5 Barrierra Wharf, Valletta (+356-2122 2332; theharbourclubmalta.com).

An unforgettable place I’ve travelled to in the past year is Mustique, where I’ve been going for 10 years. By November I’m exhausted by the pressure of work and can’t wait to get there. We hire a house, and I get out my watercolours and sketch books. I’m from Malta, which has a British 1950s feel, and Mustique is a bit like that too. I like visiting houses by the late stage designer Oliver Messel, who had a strong influence there.

The best souvenir I’ve brought home is my gondolier slippers. I buy them from Piedàterre in Venice. I have about a dozen pairs in various colours and states of disrepair. Mine are canvas, so they do get destroyed, but they pack flat and are so comfortable. From €42; Ruga dei Ores 60, 30100 Venice (+39041-528 5513; piedaterre-venice.com)

If I had to limit my shopping to one neighbourhood in one city, I’d choose St James’s in London. I’m not a huge shopper, and I’m very loyal. Along with my Anderson & Sheppard suits, for 20 years I’ve been buying my shirts from Turnbull & Asser. On a Sunday after lunch, I’ll often spend an hour or so looking through books in Hatchards – it’s my local bookshop, so I make an effort to buy from there rather than online. I’ve also been buying my shoes from Berluti nearby, in Mayfair, for 15 years. I adore my Andy loafers – I have over 20 pairs, in various shades. Berluti, 43 Conduit Street, W1 (020-7437 1740; berluti.com). Hatchards, 187 Piccadilly, W1 (020-7439 9921; hatchards.co.uk). Turnbull & Asser, 71-72 Jermyn Street, SW1 (020-7808 3000; turnbullandasser.co.uk).

My favourite apps are British Airways, as I’m always travelling; the music app Tidal; and Giphy, where you can check out GIFs of anything from cool closets to Joan Crawford. I also check the Times of Malta app to see what’s going on back home. I’m involved with MICAS, a new contemporary art museum opening in Valletta in 2021, so I need to keep abreast of local culture.