My way for lvling is to first do all my leves at 5 star. The exp is much more and once I exhaust all my leves, I goto the grinding spots where most the spawns are yellow and orange to me. So far its worked good, but I am limited to playing for hours on end due to work and family. Usually I can gain 1 rank for every 1-2 hours of solid 5 star leves/grinding.
MyStIc
VeRgIlIuS
"The one Hope for the Doomed is not to Hope for Safety"
VeRgIlIuS
"The one Hope for the Doomed is not to Hope for Safety"