Stamp Texture and Action for Adobe Illustrator
A tutorial from Biscuits & Davey caught my attention some years ago and I found it to be quite useful in adding texture to both type and illustrations. You can find the tutorial here: http://blog.biscuitsanddavey.com/2013/08/15/create-a-stamp-texture-in-illustrator/. I must commend Jared Owen Snavely for his outstanding job on the stamp texture and action designed for Adobe Illustrator!