There are other tools worthy of mentioning. The Nibbler is a common sheet metal tool for cutting and removing small amounts of metal. I have embedded two Youtube videos here about nibblers. The first video features the Bersey nibbler, which we have in our workshop, and also a conventional straight nibbler. Take note of how the Bersey nibbler rolls up the metal it removes. Each hand nibbler has it’s own best use.
The Second video (further down the page) features a simple nibbler attachment for an electric drill. These are very economical compared with buying a dedicated nibbler such as a Makita. See the price for this here: