I've shot a lot of steel, most things are common sense. That being said...don't shoot any steel with a bullet traveling over 2850fps. If you are shooting a caliber that's super fast...back up.
I can tell you a 223/556 at 75 yards can not only crater a Popper made with 1/2" cold rolled, but can shoot that bullet straight back at you and hit just below you kneecap HARD. (Still have that scar).
Also, if you have access to conveyor belting, it works great to hang your targets from. It sucks to pack your steel and stand across a canyon, hang it from the chains, hike all the way back, get all set up and shoot a chain in half right off the bat. Then, if you didn't bring quick links, or a clevis to fix it...your done.
As others have said; angle your targets down. I use 3" bolts through the target. Steel one end, and the belting, (or chain) on the other.
It goes without saying, but I'll say it anyway. Wear eye protection! I've pulled jacket frags out of the forehead of other shooters, that came from the next bay over. Would've been bad in an eyeball.