Use your spells too - bless, aid is good & effects whole party, bane etc small things that can turn the tide in your favour. Pay attention to the enemies when you mouse over them to see what statuses are in play too it all helps
Expanding on this. Try to figure out what is best used where. Taking Bless and Bane as an example.
Bless is better when you're fighting fighting many foes, or foes that are very hard to hit regularly.
Bane is better when you're fighting relatively few foes, or foes that have very dangerous attacks.
If you identify what ability to use where correctly, You're well on your way to understanding and beating encounters.