CL1.0~2.0

Do all the quests you can possibly do. Especially do the one with Larry and Remo to get your two new rings. Invest 50% of your orbs on one main ring and the other 50% divided up evenly to the other rings. You could also keep your rings around about the same level, so that if you might lose the ability to use one ring, all your other rings can still back you up. You'll be fighting a lot in The Village Greens and slowly moving on to Bill's Ranch.
CL2.0~3.0

Move on to doing the quests at Bill's Ranch and receive your 6th ring. When you reach around CL2.4ish start to gather a crew to fight the OMGWTF in Dead Man's Pass.Then slowly move on to Zen Gardens.
CL3.0~4.0

Camp out the 3 different crates at Zen Gardens. This is pretty much what you'll be doing for the entire time. Finish up Kat's Doll quest as well when you get the chance around CL3.5ish. And when you get to CL3.7ish and have a Bandage Ring it's time you should fight Cherry Fluffs near the Wish Tree and heal yourself. They die pretty quickly so it will be easier to gain a ring, orbs, gold, or ingredients from them.
CL4.0~5.0

Finish up any loose end quests you can to pull together some more orbs. Crew up with some buddies and do some runs for crates at Buccaneer Boardwalk, fighting off the Anchor Bugs. When you get strong enough (probably around CL4.7ish), start beating up Mama Saw and Papa Saw for rings and orbs. Salvage any extra rings (ones you don't want, or duplicates of ones you have) for more orbs.
CL5.0~6.0

Old Aqueduct is the recommended place to go.

You may also try Gold Beach crates should be a challenging place for orbs, and you should find it easier to take on Duneslam for rings.

You can ease it in by starting at the chest at Buccaneer Boardwalk.

you used to be able to stay at 5.1 and farm shewolf/papa saw for orbs and rings, but that got fixed for being abused until SS became available.
CL6.0~7.0

By now you can't use the chest in Buccaneer Boardwalk anymore. So it's time to move on.

Hang around Old Aqueduct and Gold Beach still doing repeat quest and just farming crates, and mobs.
CL7.0~8.0

Gold Beach will start to dry up, but doing Duneslam and chest farming is a good way to get orbs if your in the lower 7s. In the high 7s move onto Otami Ruins. There's a lot of good chests in the Ruins if you know where they are. However, the Mask is still quite a deadly foe so join a crew and use buffs. If solo you should avoid the Mask and Witch Doctors.
CL8.0~9.0

Otami Ruins Mask farming works up to 8.7. Hive World is great for orbs and rings to salvage.

If you can find a Shallow Sea crew willing to go at your CL this is the best way to level up! Be careful Shallow Sea can be very dangerous you should be about 8.6 or higher.
CL9.0~10.0

Shallow Sea farming will be your main source. Hive World is fun at any CL, just make sure your crew is all green to you. If you can find someone with the quest farming the Gauntlet in Otami Ruins is great fun! Or reduce your power to go back to any earlier area and do repeat quests.