Here's my normal leveling path:
lvl 1-15
Rockers 1 - 1 south and 1 west from Prontera, use fire endow/Mild Wind
lvl 15-30
Poporings and Marins as well from lvl 22 - 2 south and 1 east from Prontera, use VVS Wind Damascus for the Marins.
lvl 30-40
Wolves - 1 south and 1 west from Payon, fire endow/Mild Wind and an Ice Pick with Sharp8+.
lvl 40-56
Metallers - Teleport to the lighthouse from Morroc and go 1 east. Water endow/Mild Wind and an Ice Pick with Sharp8
lvl 56-71
Eden turn in quest for Maneater Blossoms, easy and not very expensive to skip that many levels.
lvl 71-80
Mi Gaos - 1 south of Louyang (Teleport from Alberta). Fire endow/Mild Wind, Grimtooth with Sharp enchants and Ice Pick with Sharp8+
From there, there are a lot more options. Also depends on the week's TI. There are quite a few bounty boards you can do now too. Getting to 99 keeps getting easier. Just remember to job change at max 42 if you're a High Thief.
These maps might not be the best for AoE grinding, but for 1v1 they're good enough and normally free of bots/hordes of players. Frankly, as long as you can handle the monster well enough and are within lvl range, it's good.
Once you're a GX, you'll be leveling off TI/Bounty boards. At this point you can just take base lvl as reward, your job levels will only matter at endgame for a little more agi. Since you're going to be autoattacking a lot, your good skills are the ones you get as a SinX and Hallucination Walk/New Poison research.
As a GX with a lot of luk, you're going to be able to gear up with Perfect Dodge to lure easily in TIs. This will make it much easier for you to get into parties. Once you feel confident enough, you can just solo the TIs.