I found a Fiesta guide about the simplest ways to level; this will give you a short, simple, yet very helpful guide to leveling from 1 to 59, as fast as possible, without skipping anything and without losing anything. Of course, maybe this guide misses something. If you know, please feel free to point them out.
Levels 1-10
Once you hit level 5, do a Slime KQ. You will instantly be about level 7 or 8, maybe even 9. From there, get all your quests, and do as many as fast as you can. Bundle em up - In other words, go out, do 10-20 quests, then turn em in at once.
Levels 11-20
These levels are best done hard and fast. If you have a higher level friend, ask them to help. Or better yet: join an academy. Get loads of quests (20/20) and ask them to quickly come kill all of your kill quests. Same basic principle applies: Bundle your quests.
When you hit 20, get some t1 scrolls, and try to get a buff from the guild you are now in the academy of, and do the class change quest. It should be relatively easy.
Levels 20-30
These are best done in the lv 20 abyss up to about lv 28. Preferably in Duos. Mage Cleric are a good duo, and archer cleric is too. Fighters can solo well enough. Remember to mob and aoe. This is your aoe training, sort of. If you get to about 27-29 and are tired of abyss, do some quick quests, but save some of them for turning in all at once. This can easily pop you from 26 or 27 into 29 or 30, and into the next level group.
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