Source image which I took of a friend in the adult woodwork class.
step 2 of 4
step 3 of 4
This is the extent of the mask that I placed over the figure.
step 4 of 4
I had a rethink after I set up the guide and this is the result - I did an Image -> adjustment->.invert
on the figure. The full colour version of this layer was set to 24% opacity.