Fighting tougher enemies!? Stab away at a foe, then step back when they attempt to counter-attack. Also, look out for a key opportunity to "back-stab", as they're much more vulnerable when attacked from the rear.
Save your special abilities up for when you really need them. That's because they take several precious seconds to refill.
Watch out for Unlimited Chests in the towns. These continuously offer up new items for your gold or silver keys, and they also come in handy if you're looking to try something new with your character.
When trying out new items, see how they fare against smaller enemies.
Speak to everyone you meet in the towns, as they'll often explain more about the story of the world around you.
Don't use up all of your Gold and Silver keys at once - try to save them for when you really need an awesome new bit of kit.
You can combine Bronze keys to create Silver ones.