You're right, many of them are tailor-made in the palace. There was such a department in the ancient palace, where there were many tailors and embroiderers who made clothes. For example, in the Ming dynasty, there was a default dyeing bureau and needle bureau, which were responsible for this matter. But there are many others, such as gifts from the emperor or gorgeous silks and satins given by others, or appointing servants to go out for shopping in the palace. As for jewelry, many of them are given to the bride's family or similar dowry, and there are also concubines with appropriate grades.