Autoclaved carbon fiber reinforced plastic (CFRP) products are supported by craftspersonship. However, it is difficult to preserve and to acquire expertise and skills inhering into the body of craftspeople. Educational tools to learn the expertise and skills effectively are demanded. Therefore, we have developed an educational tool through interviews about the behaviors of the hand-trimming expert. In this study, we performed motion analyses of the hand trimming expert and non-expert focusing on the usage of hand trimming tools. The study revealed the secrets in the expert's skills accumulated through long time experience. The remarkable behaviors of the expert were the posture to work comfortably and the proper way to hold a workpiece, leading to checking and less fatigue. For improving the skills of beginners, they can train by using the educational tool focusing on the working posture and the holding way.