Comfortable Shoes: For rugged terrain and valley hikes, you should prefer non-slip, comfortable sports shoes or trekking boots.
Layered Clothing: In the early morning during the balloon flight, the weather can be quite cool, while it will be warm during the midday hours. Therefore, "onion type" (layered, easily removable) clothing can be life-saving.
Sun Protection: The sun in Cappadocia can be quite strong in open areas. Sunglasses, a hat, and sunscreen should definitely be with you.
Portable Charger (Powerbank): As you will be taking a lot of photos among the fairy chimneys and balloon visuals, your battery may run out quickly.
Personal Medications: Your regular medications and a small energy boost (nuts, snacks) can be in your bag.