Hanigan's tape and video does go into things like working the skin to get different types of sound (open, flat, and pushed), and accenting beats... which gives you some variations in sound..... but to learn how to do it.. it is best to find someone whose style you like and watch how they do it, and listen to Irish music to see where the accented beats should fall in particular tunes..and ignore Mick's comments on holding the tipper.... he has to beat his like a cudgel because it is a 22 inch bodhran.... hahaha
slainte
alison