Druid Soloing 44+

[Handull]

Get ES Vambs and a Lumi Staff, both will help a ton. I've stopped using my lumi staff, but still use ES vambs even at 59.

Quad in FV til 46/47 if you are enjoying that. (there are other good options at this level, but i forget them)
If you get a lumi staff, go to TD and quad spirocs at 47, otherwise wait til 49 to go there. Spirocs can take you to 51 really fast and to 52 quickly if you only pull the dark blues. Unless you have crazy mana, you really need the 49 quad spell to kill the spirocs, but with a lumi staff you can use your mana and the staff to kill them, and the exp will be crazy good.
Then you can charm raptors to 55 and beyond.
After that you can charm in the perma pits to 60...
(This track is what I did, with some good exp in KC, Chardok, etc. peppered in after 56 as I camped loot as well, mostly solo)

Other good options include anything in KC. KC will be best once you have your 52 fire dot (breath of ro) and even better when you have 54 wolf and 56 root (you should really avoid certain mobs and camps until you hit 56 due to root breaking frequently). You can single pull anything to a number of safe spots and root/rot it. The mobs farther in and in the basement can easily take you to 60, though the learning curve is a bit rough. Also you'll have the rare chance at a tstaff or that caster ring, and can easily enough farm yourself a book of obulus. Though you will die a lot learning the basics, in the end its a fun zone and druids have free reign there.

KK can be anoying, and I think it also has a learning curve to it (which I haven't finished yet). What I find most anoying about KK is when you die, its a pain to get a rez out there. At least in KC there are clerics around often enough to do the job right then and there.

Oh yeah, Messianic mentioned bloodgils. They are really nice exp as well and super easy to root/rot. Just buff EB, levi, etc and tear it up. I guess you could quad them too if you wanted to pull em to land though.

Lastly, the arch magi camp in lguk is pretty nice exp well into 56/57. Its only two mobs every 28 (or so) minutes, but you get a shot at some loot, pretty solid exp, and you can do other stuff IRL between the long spawns. Not sure what level you could start this, but bring IVU pots and MR gear. Probably best to start it around 52 when you have the new DoT.