Basic Tips:
1) Do you have a Companion? Getting Griss from the Bluemist Colony will help alot.
2) The wraith hits with death damage, so death protection from rings, potions will help.
3) The necromancer hits with some ice damage so cold resist can help, but not much as it's not much damage.
4) Using potions on Ogre Might, or Giant Strength can help. You can buy the latter at Jabel if you don't have access to the Loreseeker merchant. It might be a bit of a run to go get them, but hey, they tip the scales in your favor in early game fight).
5) Getting the Sword of Shock from
Head Hunting will help alot.
6) If you're setting on a stash of gold, buying one or two armor pieces will help. In the early game, every point counts. So even if you buy one piece with a slight improvement, you'll see a difference.
7) Wolf summons. They won't last long, but they will make a difference in early game fights.