Obtain proper permits for overnight camping if applicable. When you obtain a permit, rangers will know where and how long you are camping and can notify you in case of emergency and know when you become overdue from your trip. Upon arrival at the park, check in with the ranger station. Know your trail. If you are not familiar with the trails, stop at the ranger station and ask for assistance.
Most parks offer trail maps and rangers are there to help, answer questions and offer advice.
Do not leave valuables in sight. Rangers can use this information to locate your party. Pack appropriate clothing and footwear for the temperatures and inclement weather. Remember it's always easier to take off layers than to stay warm if it gets cooler. Bring all necessary safety equipment for the activity - bike helmets, flat tire repair kits and hiking gear.