If you’re going to buy a Savannah Miller wedding gown, toss your Disney dress dreams out the window.

“For me, the major thing is that the bride feels comfortable and feels like she is the best version of herself. When the gown gets too fitted or the skirt gets too big, you can’t go to the bathroom by yourself? No, no, no! You’re supposed to be having the best day of your life, but you can’t go to the bathroom yourself?!” says the bohemian bridal designer.

Miller, who previously designed a contemporary line with her movie star sis, Sienna Miller, tells Threads that she occasionally whips up custom creations (including a slip number called “Honor” and a cape-gown) in vibrant colors for Sienna and A-list pals like Alexa Chung and Poppy Delevingne.

“We are starting to talk about producing an evening line, but we don’t have a date yet,” she says. And if that doesn’t work out, there’s always chicken.

“Sienna and I joke about opening a rotisserie joint. Every Sunday, we have a respective Sunday roast in each of our homes across the world. And people say, ‘you should bottle this gravy,’ because our gravy is so good,” she says with a laugh. “We will open our roast chicken joint on the Lower East Side, and we will wear overalls and gingham headbands. Never say never!”