These next few levels are very easy since you won't be leaving this area. Just west of where we just grinded out the last level you will find two large islands.
Note: Videos that got deleted on Youtube a decade ago used to be linked to on this page to make the guide better but I have lost them. If it doesn't flow correctly or is a bit vague that is why.
At these islands you will find level 34 Undead and level 33 Balaur. The Undead are on the southern island and the Balaur are on the northern island. The first place you will want to go when you get here is to the Balaur, you will grind these until level 32 or 33. What level you grind them to will depend on how hard the undead are for you.
Once you reach level 33 it is time for you to head to the southern island and kill the Undead. When grinding the Undead you have a much greater chance to be ganked. Mainly because the Elyos come here for a few things and also it is close to their easy access Upper Abyss entrance.
If you're getting ganked too much at the Balaur you can always grind at the islands inbetween the Balaur and the Undead. These islands hold elementals that are higher level then the others you grinding north of where you enter. When you reach level 34 you will want to head to the southern island and grind on the undead here. The undead will take you to level 35.
If it is too ganky, as seen in the last part of my video you can always go back to the Balaur, start a group to grind here or god forbid, leave the abyss =P . Chances are while you're alt tabbed reading this you're being killed. Once you reach level 36, either in or outside of The Abyss it is time to switch areas.