Sunburn is a particular problem. Wear clothing such as long sleeve shirts and long pants as they protect from the sun, scratching branches, and insects. Bring sunscreen and a wide-brimmed hat.
A note on footwear - approximately 80% of the hikers wear full hiking boots and thick socks. While running sneakers may suffice (and Choco-style sandals may work for a few days), your risk of injury is higher, and much of the trail involves hopping around on wet and/or sharp rocks. Choose conservatively, depending on the length of your hike and your experience.