Before & after: Sophie Ashby shows how to add character to a new build flat

Which styles or periods of furniture would you recommend?

I don't generally look for a particular age, genre or style - it's about each individual piece. The magic comes from using surprising combinations - something Regency next to something from the Sixties, for instance.

But Modernism will always have a timeless appeal. I love the story behind Modernism: the departure from the classic into the unknown. The style represents a time when designers were really looking to the future.

Are there textures and colours that work particularly well in a 'modern white box'?

I love using earthy tones and natural colours. The power of colourful paint and plants must be harnessed to create atmosphere in a flat like this.

One of my favourite colours is 'Panel' by Paint & Paper Library, which we have used in the open-plan living/work/kitchen area at South Bank Tower. It subtly fosters a cosy atmosphere in a space that would typically have been painted in a pure white.

Where should you splash out and where should you save money?

Quality over quantity will always be my mantra. It's all about collecting a few quality pieces, like a beautiful Modernist chair or a coffee table from the Forties, and using them to speak for the rest of room.

I create an interior space as I would curate an art collection: with much consideration over each piece, its setting, its neighbours and its position within the room. The key area in which to invest is original artworks - they last forever and increase in worth, whereas the value of most lighting and furniture sadly depreciates.

Second to art are antiques. Scouring markets, eBay and 1stDibs is time well spent and you often come across a complete bargain if you are willing to oversee a bit of repair and restoration or upholstery. Books and plants are also great ways to inject a bit of life and soul without spending much money.

How do you arrange furniture in very regular-size rooms?

Scale and proportion is everything. In a regular-size room, concentrate on making sure the style of your furniture is relatively fine and not too clunky or oversized. Choose a sofa with neater, finer details such as metal legs rather than a plinth base. This will encourage lightness as it won't feel like a big block in the middle of the room.

Rugs are useful for dividing up the different zones of a room and anchoring the furniture to those spaces. If you buy a rug that matches your sofa and armchairs, the area will feel defined. Another rug, perhaps a skinnier runner-type one, can then designate another space in the room to establish a study zone or dining area.