The foil should not be cut with a knife, but with scissors. I always cut 5 pieces of the packing tape with a length of approx. 5.5 cm. The individual pieces should be of similar length so that the thickness of the foil cone is always the same. The pieces should not be much longer than 6 cm. Not much shorter either. Because otherwise there is a risk of not covering the entire wrapping aid with foil. I glue all 5 pieces in a row on the cutting mat. That way I always have the pieces to hand and I can't miscount when wrapping the foils.