Madeleine Spencer Long-term style icon and eternal It-girl Sienna Miller has always done beauty her own way: insouciant, intuitive and totally unfussy. Here, she sits down with Madeleine Spencer to share a few of her best-kept beauty secrets. I don't do ice baths . I don't want to get freezing cold, I just don't. Tori, my best friend, has a cold lake near where they live and I have jumped in there and you do feel incredible afterwards.