I create pattern first by drawing on paper, but it out and roughly get the measurement required. Then create pattern using free software based on those measurement, print and test again and again before the final pattern:) Although it is time consuming but it is worthy when you finally created what you imagine. If you like create thing, hand craft, please join me at https://www.youtube.com/c/HappySnailDIY https://www.instagram.com/happysnails20/ https://www.etsy.com/shop/HappySnailDIY