Take clothing you can use to add layers or remove layers as necessary. Do not take cotton-based clothing as it retains water, does not insulate, and can cause major temperature problems. Bring raincoats and other weatherproof shells if you think there may be any chance of dealing with weather on your trip. Consider bringing light and breathable long sleeve shirts for sunny days to protect against sunburn. Put sunscreen on exposed skin before hiking.
If you will do a longer trip on the Appalachian Trail, make sure you have shelter and a good place to sleep. Take a backpacking tent, sleeping bag, sleeping pad, and a rain tarp. Proper shoes, such as hiking boots, are essential gear for longer hikes on difficult terrain as they provide extra support. You should always pack a headlamp in your backpack on any trip in case you end up hiking when it is dark. Navigation supplies, such as a map and compass, are good pieces of gear to have if hiking in an unfamiliar area. You should also think about bringing a lightweight stove if you plan to hike overnight on the trail. It is wise to have a small first aid kit handy to treat minor injuries. A cell phone is a useful asset if you are traveling where you are certain there is cellular reception.
You must bring more than an adequate amount of water for any hiking trip. This will keep you hydrated if you end up staying out longer than planned or get lost. Water filtration devices are a tool to have if you run out of water on a trip. Snacks, such as trail mix or fruit, can give you energy during a hike. If go on a longer trip, plan what food you will eat for dinner and breakfast the next day. You can bring individual ingredients to cook full meals from scratch or consider bringing dehydrated food to save weight.