This is more of a offpeak guide as you wont be getting many mobs in CoM solo during peak hours but here was my leveling path:
1-15/20 (any newbie zones)
15/20-40 Unrest
40-43/44?? Low Guk Bats n Bugs ( solo not grouped, Fin' amazing xp )
43/44 CoM Entrance/Stables - Haze Golems are you bread and butter at this level...you milk those golems for XP ( avoid Fog golems like the plague)
45-51 CoM
*DEEPWATER HELM TIME* Arena huts/Temple/Stables (there's one hut with 4 spawns you can take with average gear, then pick off a few singles) (still avoid Fog golems, you can kill them but they are NOT worth it)
See this video here (
https://www.youtube.com/watch?v=2S2jofkXMC0) for the hut I soloed
See this video here for Temple solo and the reason why you avoid Fog golems (
https://www.youtube.com/watch?v=XM6WVpuY4co) I also ding 51 in this video at Temple.
From 51/52 Onward I went back and have done a bit of KC (not much, it's rough) (see video here of my dinging 53 in KC
https://www.youtube.com/watch?v=ZVIS6Uxyrm0) and mainly stuck to Guk and a bit of Grobb guards (till they greened out) for xp... I am now almost 56 in Guk and hopefully will have more video's of me soloing all the camps in Guk when I get time to make them. I only have Frenzy and Lord to slay and I've decapitated every name in Lower Guk dead side solo.
As a side note, around level 54/55 Dar Knight's became fairly easy, they range from straight kills with no helm healing/healing needed, and sometimes 1 or 2 heal up sessions. I think by 56/57 they will be straight easy kills but not sure if they will green out by then. At present I am leveling at a spot that has 4x dar knight spawns and it's suiting my casual play style atm very well as I am able to cycle those 4 mobs + 1 other when needed and kill them down fairly well with med breaks etc. between no problems.
One day I intend on making a guide with videos such as the above ones, just don't have time right now.