awww. Hmm I pressed the thin piece of green clay onto the surface pretty hard and then i also texture it kinda hard with the foil, then scrape it off wit hthe knife. Don't care too much about how each piece looks cause it's random. Just make different sizes. Also, make sure the clay is THIN. I hope it helps >.< good luck!!
I love your tips! For a bloody beginner like me they're invaluable <3 (Although my stuff is a much larger scale, I make props for BJDs and they're more like 1/3 than 1/12. Oh well, beginner friendly, huh?)