Thank you so much. I have been watching so many speedpaints and tutorials to find how other people accomplish this but not one of them explained this move. Now that I think about it, it might be too obvious for those who are so used to PS to remember to explain the technique.
To avoid overdoing the selection, use the Ctrl Shift C command, then put the pointer over the underbase layers thumbnail (if you have one for the dragons head) and hold Alt + Shift then click. You'll notice your pointer turns into a select icon with a X in it. this means it'll only select the cross section between your over selection and the underbase.