Whats the absolute fastest way to get to level 30?

I want to level up a couple characters on old accounts to 30 so they can participate in the hot time. What sequence of mobs would ideally be the fastest with 0 mesos?

Killing area bosses all around victoria gives pretty crazy exp. You can usually get enough exp to lv up instantly. My routine is to kill all 3 types of mushmoms in henesys in all chs, then finish up lv25-30 at golems.