In this paper, the mainly defined factors such as color, fabric, model of a commercial collection which was prepared for a commercial brand were examined. Five t-shirt designs existing in the collection were chosen and all the collection preparation step details, aesthetic and technical quality control methods from design to final garment were observed in a medium-size apparel company. The achieved results showed that for preparing a successful collection, first of all, the quality control steps must be determined for each style, and then both aesthetic and technical quality controls should be made by qualified people. There has not been enough study about garment collection preparation steps in the literature. The results of the study will be helpful to apparel manufacture industry for preparing better and quality collections.