Agree, lots of techniques out there. I find that for my purposes, I use pieces of makeup sponge (as in lady's makeup), and then just dab the underlying color on top of the color coat. Kinda like the chipping effect that plastic modelers use. Vallejo makes a chipping medium that in process is similar to the salt or hairspray technique. Years ago, in the Gazette, articles by Greenberg and Nash, they used rubber cement didn't they?