It’s Christmas countdown week! So no one can blame you for wanting to wear sequins to work – well, that was before you saw Jennifer Lawrence in the sleekest tweed look ever. It's all down to her monochrome palette and 60s shapes, so pair your black roll neck with a cream tweed skirt and style with high heels and a checked coat, worn open. Amp up the attitude with cat-eye sunnies and you'll be strolling out the office like…