BOTTOMS UP: When you cross Grace Jones’ fierce style with Audrey Hepburn’s elegance, what kind of shoes do you get? Ask Estelle, the pop star contemplating creating her own shoe line after dabbling in accessories for a special project with Belvedere Vodka and designer Jonathan Kelsey. “I love accessories,” chimed the singer, who was wearing a white Martin Margiela jacket with matching trousers and loads of jewelry at the recent Belvedere Black Raspberry launch. “And I’d love to have my own line.” The Belvie bag, codesigned by Estelle and Kelsey — with a secret pocket to hold a bottle of vodka — retails for $1,400 at Jeffrey and was launched at the fete.