A die cutter or templates are great if you plan to use pre-cuts or are relying on a scrap bag, but if you are using fat quarters or yardage, you'll be most efficient and have the least waste if you cut strips the width of fabric, height of desired tumbler. You can cut your tumbler pieces out using a regular ruler and marking the desired angle on the ruler either with tape or a marker -- no waste at all except for a small piece at the beginning of your strip.