A method of forming a finished film comprising extruding a molten polyethylene comprising a diene terpolymer modifier through a die opening to form a film, wherein the diene-terpolymer modifier is a terpolymer comprising ethylene-derived units, C3 to C10 α-olefin derived units, and diene-derived units; causing the film to progress in a direction away from the die opening; cooling the film at a distance from the die opening, the distance adjusted to allow relaxation of the molten polyethylene prior to solidification and/or crystallization upon cooling; and isolating a finished film therefrom. Desirably, the polyethylene is a linear low density polyethylene, and the die and cooling is suitable for forming a blown film.