Cut the plate to desired dimensions, leaving some extra 5 mm from each side. Clean the plate. My best results are when I use fine sand paper and ethyl alcohol. The sand paper not only removes the oxide layer from the copper, but makes the surface abrasive and the the toner adheres better. The alcohol removes the fine dust or grease from the plate.It is good to put 3-4 layers of plain paper between the plate and the working table. This way you prevent the heat to dissipate from the plate to the table and will have a "cushion" when apply pressure with the iron.Put the transfer paper on the plate with the toner touching the copper.Use whatever available to secure it firmly, so it will not move when you start ironing. Thumb tacks are my choice. Use more for bigger plates.