Here's some great suggestions and links share by people from the Crazy Quilt List ...

   Velvet Embossing
I've found embossing on velvet works best on rayon (or mostly rayon) ... the heat seems to "melt" the fiber and there's a better imprint. Cotton velvet seems to resist the heat and I've not gotten as definite an impression.  Here are some links shared from the CQ List:

Embossing Velvet

Velvet Stamping

Fabric Dying

Discharge Dyeing with Comet Liquid Gel
 

Definitions

Fabrics, Fabrics, Fabrics says

Button Definitions

Lessons from Priscilla

Leslie Levison's "Crazy Quilt Patchwork Block" Online Class

Betty Pillsbury's "The History of Crazy Quilts"