Leveling Guide

This game is really easy to level in if you know how to do it. I have leveled multiple lvl 80s using this strategy with very little effort. The first 30 levels shouldn't take you any time at all to make. You can get to lvl 30 in day 1 by just doing the quests and running dungeons. NOTE:you only get 1 stamina every 10 minutes and it takes 5 to do a normal dungeon so you should always do at least 1 dungeon an hour. Once you are above level 30 you are going to want to focus more on dungeons, make sure you are never sitting at full dungeon stamina. You will want to run the highest level dungeons as many times as you can. This will also help you to not hit dead spots in questing where you only have a quest to reach the next level. A few other things you are going to want to do is get double experience cards from the voucher store and make sure to use the ones the game gives you. A few other things you can do to increase your experience gain is make friends. Find people around your level and link up and do dungeons together. Add them to your friends and gain friend levels. Group when you are in the same zone as well, you get credit for each other's kills so you don't even need to be doing the same thing to increase each other's experience. Another option you are going to want to consider is spending the 5 dollars to get vip3 which unlocks among other things auto use soul skill. This is a button you can check in auto attack options that allows your character to use the soul skill you equip as soon as it fills. With this ability and the self cure soul skill equipped you can actually kill forever without dying on most classes while leveling up. the other notable unlock for vip3 is remote warehouse which virtually doubles your inventory.
Once you reach level 55 you can enter leven harbor, and once you can get here you and your friends can really level while you sleep in dark passage. You get there by going through the waterway under leven harbor. It's the highest level zone in the game that is a non PK area. It helps to have a guild that regularly groups up in here with auto accept group invite selected. You and all your guild friends can gain about a half of a level or more every night in there while you sleep. You are still going to want to  dungeon as much as you can do all your quest and use all these tactics and if possible start doing heroic dungeons.
All together you should be able to get to level 80 in about 3 weeks or so pending on your playtime.