And if you happen to be in a crouch position welding vertical or overhead, never put your knee on the ground or floor, one of those sparkys will go right under that knee and light you up, instead place your knee on the steel toe of your boot on your opposite leg. In my experience, MIG vertical, weld downward, and move fast. Overhead, same, move quickly, if you hang around you'll simply heat things up and it will all fall out. I typically bevel joints, get a good hot fast moving root pass, then turn the heat and wire speed down just slightly to be able to control the 2nd and 3rd passes. Like any other weld process, practice.