Poster Designing

Need a poster designing showing that my food stall now sells Iced Frappe Drinks. I need something sexy that looks WOW and wants customers to think i want to buy a cold drink after seeing it. I am part of a franchise so need to use specific fonts and colours but i have all of that. The franchise is called Auntie Anne's We sell pretzels predominetly but have now started to sell drinks as well.