Beer is Good for Adventure
My biggest tip is to always, always, always, go to the local watering hole and ask the bartender and servers about the low down on some great hikes, boat trips and beaches. Or just generally, what they like to do on their day off. If you are interested in something amazing you heard about in that area, just ask them more. Living on Maui, I try to guide and help people as much as I can with stuff they need to check out (but not giving away all the gems). And hey, bonus points if they take you on an adventure!