At the Toronto Film Festival in September, Styles debuted another interesting accessory: a giant green lapel flower. The singer debuted the look for the premiere of his movie "My Policeman." To nail this look, match a flower or plant — real or fake — to an emerald-green blazer. Green trousers and a green bag — preferably all in different shades — will finish the look. Picking a flower around the same size as Styles's would give you one chic Halloween look, but if you want to go for humour, an oversize flower or plant would definitely make your fellow revellers laugh.