At level 15, get as much +AC gear as you can (rings from seaport, midnight dragon stuff if you can hire someone to gather etc) Otherwise, scavenge the ground around midnight dragon for the moonstone stuff (or buy it if role allows). Once you have "divine" in all AC categories except elemental/spells/whatever then it is time to go train.
Go to barovia mists, follow the exits into the northern forest half of barovia, get all the skeletons/wargs/etc tracking you, lead them into the mists. Hit mist wraith while your tracking mob of random undead/wolves beats on you. The wraiths respawn in the tick they are killed. Watch your health, most of these things should be "missing" you because of your high AC. When your health does start to get a bit low (due to kicks/dirt/whatever) wait until the wraith fighting you is about to die, when it does just walk towards the exit in the "space between heartbeats ;)".
Run to the open sea to rest and then head back and rinse/repeat
Another option is the possessed villagers by dale
If a hider class, and neutral/evil simply gather up every commoner in voralia and track them to dagdan, or somewhere. Tank them until your health gets low, then flee/hide and rest - this also works with invis.
once your defenses are done, now it's time for aim and weapons. Rank up until 17/18 and then head south of hamsah to the encampment (all the guards there have shields, and armor). Fight these guys to work up weapon skills and aim/trip/whatever. You will rank up until like 21 here doing this.
Now onto spec skills/whatever else happens in your 20's. Go to the monks in moudrilars and spam it on them, taking each one down to convulsing (they don't chase and only re-engage if you sleep in front of them once aggro). once the 1st is convulsing, move to the next. There's like 20 or so of them, and by the time you are on the 20th the 1st will have healed.