I generally use the +% on the highest growth rate for my intentional use, and -% on the lowest growth rate.

Also take note the correlation between Tai/Nin (when intended use is dmg) and the ninjas skills.
Example: Ninja *X Has Nin Mystery, Tai/Nin standard. Nin Chases, but the Tai growth is SLIGHTLY higher than Nin, Ill still use mood on Nin.