When I leave the house, in addition to the work materials in my backpack, I take my smartphone, wallet and house keys, I also always have a notebook and a pen with me because I don't know when they might come in handy, as well as a napkin because I might need it at any moment. I will also take a power bank and a charger with me because I spend most of my time away from home and I don't know if my phone will be charged for the whole day.