Any advice for xp grinding?

I finally managed to get an item from the new Lightning set, but I can't equip it until I'm LV 50. Is there a way to xp grind to raise to higher levels?

You could buy an exp boost potion, think it works for a day. Or go for 3 stars on all levels available. Beyond that it's just grinding like any other game. Auto play makes that a little easier.

how can i get that set? lvl 67 but only rare items.