In the garment industry, upgrading from mass production to mass customization is imperative, due to ever-changing fashion trends and customers’ increasing personal demands. Based on pattern variations, several practical mass customization methods in terms of custom-fit and co-design are developed in this study for cutting-related processes (i.e. the sizing process and the cutting process). The increment of size number by generating additional sizes and the expansion of size capacity by setting multi-sized darts are two custom-fit methods, while material (fabric) variation by spreading “rainbow plies” and module variation by making a stepwise cutting are two co-design methods. Compared with existing mass customization methods mainly related to the garment design processes, the proposed methods emphasize the garment manufacturing processes in order to resolve the conflict between personalization and cost. A case study on the women’s basic straight skirt is conducted for the performance evaluation (about personalization and cost) of the proposed methods. The experimental results demonstrate the ability of these methods to significantly raise the personalization level with an acceptable price in garment customization. This study provides a reference for garment manufacturers to make proper production strategies, enabling garment mass customization.