As Karen Shultz indicates in the tutorial, brushes can be used in many ways. In this layout I combined two of Jopke's Edge Brushes to give the wood background some darker areas. Then I used Vicki Robinson's texture brushes as an eraser to remove some of the wire and to grunge up the title.

Lots of fun & experimentation with blending modes. Ultimately settled on my usual blending modes. Added colour fill over watercolour overlay & set blending to screen, 100% opacity. Clipped photos to framed masks, clipped colour fill to photo & set blending to overlay, 67% opacity. Set blending...