this guide is good too..
InsecureSpike has mentioned this in a few of this posts….

i use it and always the extended procedure… it uses the usb device’s Partition unique GUID & Filesystem UUID incase you have any other usb storage on your Pi, for example if your using it for Retropie & another OS/distro also from what i gather its safer than just assigning drive names

https://www.raspberrypi.org/forums/viewtopic.php?f=29&t=44177&hilit=move%2broot%2bfs%2busb%2btutorial&sid=2503f9ffe9afaa2edb49aef4537a862a