How to etch iron without fancy tools

No engraving tool? Etch it with copper sulfate!

A pound of this stuff [Amazon] costs very little and will be enough to etch everything in the house. As the presenter notes, if you're etching a chisel remember to scrape all the "fat" off first. You can use the remainder as a fungicide and fertilizer in your expansive onion garden, or to electroplate your razors.