Following we list you two kinds of method to level in Rohan. Have a look as that can help you more or less.
Party Grinding in Dungeon
This is prolly the second best way to level in this game. This is depended on what class(rohan gold) you are when grinding in a dungeon. For example, if you are a healer, dark elf, archer type you may have a lot of trouble staying alive in the beginning dungeons. You may die more times then its worth and will not be very productive.
Howerver tank type characters(rohan crone) will level very fast in dungeons and rarely die. Unless the whole party dies and they get mobbed by counltess monsters. So its very important to find a good healer. Another great bonus about grinding in a dungeon is that you can obtain some pretty nice gears and some orbs/skill stones. You will also run across a boss here and there to get some extra exp boost and some great items.