Before each battle, you’ll get to choose with advantage you want to give your crew (so long as you don’t break the judge’s rules for that battle). You should always, always choose an experience boost over any other statistical advantage. You’ll rarely (if ever) run into a battle where you should be challenged to the point that you’ll need a mild speed or strength boost, for instance, but experience is always a hot commodity that should be gathered when and where you can. Giving yourself an experience boost during each battle will let your characters level up quicker, and ultimately this will lead to an even stronger party that will never need statistical advantages in battle. Continue to repeat this process and you’ll be working with a really strong crew before long.