The Full Support: Levels 15-70
Full Supports level FAST, only if they have plvler or partner with them at all times. Leveling to 70 with an FS is the easiest thing you can do. I have NEVER made an FS, but my sister has, so leveling is very easy. With max heal and at least 30-50 INT, many will want you as their FS or leecher. You will be the AoEr's lover because they will rarely die with your stick spamming for his life. At lv15, you may not have many places to go, but put Heal to lv10 at first, so that when you get to lv20 you can max Heap Up, and then at lv25 you can max Haste. With these two buffs, Mercenaries, Assists (1v1 and AoE) and Acrobats will want to plvl you.
At lv15 I suggest you either go look for a plvler 19 levels or lower and join an Advanced Contribution Party. A full one that is. It will give you lots of exp. Go to the Totemias if you can, because most levelers there are around lv30+. Go and ask nicely if they need an FS. Sooner or later you might find yourself as a plvler's official FS, and that guarantees plvls all the time you log on! (That is if he's logged in too)