Gwen Stefani's outfits always include some kind of customisation to match her uniqueness.

The 'Let Me Reintroduce Myself' hitmaker's stylist Sonja Christensen has reflected on Gwen's ever-evolving style over the years, and how she has "embraced her feminine side and her iconic tomboy style" and has never been "afraid to take risks".

Sonja told POPSUGAR.com: "From the '90s compared to today, I'd characterise Gwen's style as a beautiful evolution; a mix of pop, punk, a hint of country meets high fashion, and a bit sexy. Just as she's evolved as an artist, so has her style. She has really embraced her feminine side and her iconic tomboy style from back then. She has added more pink, a little sparkle, and fringe. Gwen isn't afraid to take risks, which is why she is the style icon that she is today."

Sonja added how every piece the No Doubt star - who is married to country star Blake Shelton - wears is unique because it's been altered in some way to make it a "custom look” - and that can take hours to get right.

She said: "Almost every one of the pieces [Gwen] wears has some sort of customisation, so just like her, each piece is unique! Most recently, Gwen and I collaborated on a custom look for one of the blind shows on this season of 'The Voice'. Her vision was a sparkly superhero vibe. I got in touch with Traver Rains, who was formally the designer for Heatherette, and Ske Drynan of Dulce Bestia, both of whom were quarantining in Montana at the time. They didn't let that stop them! They got to work and started sketching. I'd Facetime with Gwen while she was in Oklahoma at the time and showed her the trims and materials, and we'd tweak things along the way. After four back-to-back fittings in LA, it came out just like we had envisioned!"