So more detailed advice:
Reducing Death Damage:
Equip a few Death Ward Rings (+30/+40 Death), a Blessed Necklace (+15 Death), a Nivarian Cloak (+12 Death), and top it off with a Potion of Death Ward (+20 Death for 60 s). You could also use a Greater Potion of Death Ward (+40 Death for 60 s) or use the Cloak of Iron Will to help avoid being stunned.
Reducing Physical Damage:
Using ring and necklace spots for death resistance allows you to equip your best armor to deal with the physical damage. Using a potion of shielding (+12 Def) at the start of the fight can save a few hitpoints but in the middle of the fight, you might be better served using healing potions.
Increasing Attack Damage:
Potion of Giant Strength, Potion of Heroism are good options here. The latter also increasing defense and restoring some hit-points.
There's some class specific tips, but that's getting into the weeds of player build.