First things off the top of my head.
Welcome back to shamanhood. If you're really interested in rounding out your skills, there are several zones you can grind in to get AAXP, and maybe a bit of gear.
BOT. Mobs summon, but you should be able to get your defense and melee timing down rotting and meleeing these down. They drop pretty quickly at 70+, so decent AAXP. Southside is resistant to disease (VP), but other wings are not. Do this meleeing with pup and leopard on yourself to get your tanking and splitting skills smooth. Then move on.
Sol Ro. Do the alternate Sol Ro access quest and get in there and try your hand at 2 at a time. The mobs come in pairs after the first single wanderers, but you can have fun pushing it to the edge and maybe get lucky and get some Ornate drops. Ornate pants for the clicky root is your main goal here. If two is too many to handle solo, then just skip this zone.
Wall of Slaughter. Moving into Omens zones, see if you can handle splitting and root rotting the murkgliders in the caves just north of the zone entrance. If you need to snare them, get some snare potions or a proc snare weapon like the . It's good practice to find your best melee weapon with innate and aug procs, and bandoliering that in and out with something like the snare weapon. If your gear and skills are good enough, try tanking for a group at the left wall in WOS. If you get a fast puller or pull yourself and punt adds, it's semi-decent AAXP and fun to boot, and there may be some gear upgrades for you as well off the named. Move on to either the cubbies or the NW cave mobs once you get bored of that. Then move on.
MPG. You can root-rot some mobs in there, and if you've found some decent HP and AC gear, and a good AC shield, you may be able to tank a few of those mobs. Maybe, maybe not. Some more gear upgrades, like a couple rings and the 20 AC aug for your shield from Blindhunter.
The Nest. The uninstanced Nest is a great place to learn to split pull using root and VP. They do not summon, so you should be able to root-rot them down. Good place for XP and to find the best balance of DOTs to get continual kill time. If you get a 3 man group, you can do the instanced version of the Nest for better XP. Watch for Metallic Drake Scales (MDS), as they still sell for around 4-5k each.
The Hive. Same thing as the Nest, but better XP. Something to try, but it can be difficult and boring after awhile if root-rotting isn't really your thing.
Icefall/Direwind. You can root rot in these zones. The Ice side mobs have more HP, so slower going, but VP will stick better. You can pre-debuff with PD/MD in Direwind and still get good punt results. More XP here, Icefall bracer quest for gear upgrades. Also TSS tier 1 armor for now, upgradeable to Tier 2 if you get into Ashengate/Frostcrypt for the power sources.
Aside from these zones for tanking, splitting, and root-rotting skill-ups and a bit of gear, look up some of the gear quests found on this site. It'd be great if you could grab the Qvic sleeves with the right group, but barring that, get TSS visbile slot gear (chest, wrists, legs, etc), since it is about Qvic level minus the AC and focus effects.
DON. Make sure you get Leopard from the DON merchants, and as many HP augs as you can. DON merchants also have some purchaseable focus augs, like spell haste, burning affliction, and improved healing.
DOD. If you manage to get a group, quite a few of the DOD missions will give you gear upgrades. Lingering Sloth is the spell you want from here, if you're not getting TBS and going for Lassitude.
POR. Get Nectar of Pain from the POR zone Devastation; there is an alternate quest that is easier than trying to get the 9(?) different skins from different mobs. NoP is going to be your best DOT for damage and efficiency (unless you get Nectar of Agony). Also, it's really easy to do the 55 Idol of Malo quest for the AE debuff-on-a-stick.
As for AAs and spells, get Call of the Wild when you can, and work on your defensive AAs. Make sure you have your latest HOTs, Balance of Discord, and your latest DOTs and you should be good to go.
Get a Spiritstone so you can bind wherever you want using Gate as a ghetto self-evac if necessary, or to shorten corpse runs if you don't want to do the guild lobby summon and run back thing.
I'm sure there's much more to be mentioned but these are the first things that pop into my head. Good luck.
Oh yeah, if you're a troll shammy, you might be able to get that snare necklace if you worship the right god. Huge if you can.