What build do you have, Flandy? Chaos or Order? Maybe you aren't playing and leveling in a way that fits your strengths. I'm not a pro, but I think you should take into account:
- Elemental weaknesses are important. Try to remember which element an archfiend is weak too. If you hit enough an enemy, they'll get stunned for a short amount of time (it's like 20s, I think). Elemental weaknesses go this way:
Fire, Wood, Stone, Lightning, Ice, Fire
- Chainned attacks are useful for dealing a big amount of damage to enemies afflicted by X Hell. It's hard to explain, but it works this way: A enemy is weak to fire. So you attack him with fire until he is in Burning Hell. Then you use a Ice skill and attack him. The Hell state will disapear, but he'll suffer an insane amount of damage.
- Learn which skills are better for you. I love melee combat and I like dealing a big amount of damage will paying attention to dodge attacks. I loved being a melee DPS at WoW (Ret paladin, Rogue, Enhancement Shaman) so it was a given i'll go for a chaos build. Maybe you fit Order, or Chaos, or maybe Neutral. Find what makes you feel comfortable. I think the game is pretty well balanced
- Use mind eye to find the cursed parts from the archfiends. Destroying cursed parts give you points and locks some enemies skills. When you destroy the Harpy's throat it'll stop using that sucking skill, for example.
- Learn patterns! There are animations before archfiends use a attack. Learn which one means what and how to answer to that skill (block? dodge? run away?)
- Play with me!