A flexible pouch for packaging a product includes a front panel and a back panel, each having an upper edge, a lower edge opposite the upper edge, and side edges extending therebetween the upper and lower edges, that are joined together at the side edges and the lower edges to contain the product. The front and back panels include an outwardly projecting crease that forms a guide pocket for separating the panels, prior to filling the pouch with the product, and the crease is straightened out when the upper edges of the front panel and back panel are sealed together. A method of forming and filling the flexible pouch includes the steps of forming the panel, and forming a crease in each of the panels that projects outwardly and extends longitudinally along each of the panels. The method also includes the steps of joining the two panels by sealing together their side edges and lower edge, such that the crease in one panel opposes the crease in the other panel, to form a guide pocket, and separating the two panels by forcing apart the guide pocket. The method further includes the steps of filling the pouch with the product and finishing the pouch by sealing together the upper edges of the two panels, such that the crease in each of the panels is straightened out as the upper edges are sealed.