How can I add texture to a Photoshop brush?

I've always been intrigued by digital art work that imitate the look of traditional mediums - that have this traditional aesthetic to them. Whilst browsing for tutorials on how to do this, I stumbled across this tutorial by Scott E Franson - I went to experiment this for my visual language class on shape and texture:

This is the texture that I scanned in from black paper that I textured with white acrylic paint:

I decided to select this portion of the texture:

Edit >define pattern

I increased the scale in this to make the brush strokes more visible:

Different texture created with a sponge:

I experimented with a different brush setting on the left - not sure what they really do yet:

Kyle T Webster's pastel photoshop brush: