I really liked the techniques used by CP9, so here's what I think the order of difficult is to master, number 6 being the least hard etc
6:Kamie - A dodging technique in which one moves like a piece of paper in the wind
5:Shigan - Hardening a finger as a bullet
4:Tekkai - Hardening the entire body as steel
3:Soru - Stepping techique which involves tapping your feet more than 10 times per second(it's kinda like shunpo sonido and hirenkyaku)
2:Rankyaku - Making the force of the wind from a kick powerful enough to slice concrete
1:Geppou - Stepping onto air as if it were solid ground!