People who have been selling handmade items for a long time can tell you that there are lots and lots of mistakes to be made when operating their business. Of course that's just a part of life, making mistakes and hopefully learning from them... But sometimes we can learn from other people's mistakes as well. My top ten list of mistakes to avoid when selling crafts starts with underpricing work. Many crafters forget to pay themselves when setting prices, and some have even lost money by undervaluing materials. What is the biggest mistake you have made in operating your craft business?