Lady's' magazines frequently included patterns for caps, often they showed the inspiration of the popular "oriental" influence.
Both velvet and wool are common as the base fabric, embellished with embroidery or braidwork. The colors were usually strong and contrasting, a spot of color in the overwhelming sea of black gentleman's garments during the period.
Linings were typically silk or polished cotton, often quilted.
I just finished this cap; it is black velvet with a paisley and trefoil design chain stitched in silk. It also has the obligatory tassel, attached to a crochet covered button.
This cap will be worn with a cotton lounging jacket in an eye-popping combination of purple, orange and gold - get out your sunglasses!