Usually I tend to use the iPhone WiFi hotspot feature. But lately, I had to switch to USB tethering, because I had to work a whole workday using the hotspot feature. USB tethering saves battery and the connection was more reliable for me. Please note, that you need to install iTunes to use USB tethering, because the necessary Ethernet driver is only available with iTunes. Without this driver, Windows won’t recorgnize the iPhone as an Ethernet connection.