If you lose over half your stamina in a fight, don't bravely soldier on - it could leave you in a near-unwinnable scrap later on. Keep trying until you come out with the bare minimum of damage.
Have a pad and pen handy. You'll be given clues that could come in useful later on.
Appearances can be deceptive. Don't be fooled by friendly faces - if you sense a trap, you're probably right.