Only thing I can suggest is to check out the guides such as
this one: I'm not sure if the locations are exactly the same in DKS (I still have ED installed) but hopefully it'll give a few useful clues. Making sure your armour & weapons have decent charms and enchantments will help.
As for the forts, they
are tricky. My usual tactic was simply to change back to human form when things got too hairy as I tended not to be so vulnerable that way, even when surrounded by Black Ring types. Just be careful when changing as a missile or magic blast that's targeted you will still hit after you've changed back to being a human, and it can hurt!
