Take your time, a battle that lasts 5 minutes without taking damage is more rewarding than a 30 second battle where you have to use your resolve.

Also one of the things I found useful was to not bother with parry's and just use dodge to counter attacks, parry's can be really rewarding but can be hard to get the hang of and can cost you a lot of health if timed incorrectly.

Final tip, make sure you are using the correct charms for your situation i.e use charms that give you more resolve and health gains from using the resolve, also minimising incoming damage and maximising damage output. I usually travel using the traveller's attire which I have fully upgraded as it uncovers more of the fog of war, then as soon as I enter into a battle with lots of enemies I switch my outfit to something more battle ready with the appropriate charms assigned