Half the battle is working out what things are called. I bought a "hand shear" which is like a heavy duty guillotine operated by hand through a big lever. While they had them from $99, I spent a bit more ($169) to get one with a 300mm blade length.
I have owned a small hand brake metal bender for some time but the inability to cut metal cleanly has hindered my use of it so far. Hare & Forbes have a great range. The one I bought is second from the left.
As a first project I bought a rectangle of 0.5mm aluminium and re-made a box lid to replace one I messed up for the uBitx.
My dream is to be able to make small custom boxes for projects. There is much to learn but happily YouTube is a great place to see how to operate this kind of equipment. Peter, VK2EMU, kindly sent me a link to this video about making Aluminium enclosures from Chuck Adams, K7QO.
I've had a shot at a small box out of 0.5mm aluminium.
It's pretty rough but not bad for a first attempt. The trick is to make the top part wider than the lower part by the right amount.