This video discusses hacks, tips, and tricks for working with sheet metal using basic tools. It goes on to show the builder building using metal fabrication to solve an organizational problem in the garage.
The first step is to make a straight long cut in the sheet metal.
The video shows this cut is made with an angle grinder. He is using angle iron clamped to sheet metal as a guide. Using slight pressure, you can make a straight cut with the grinder.
Then Tim makes cut lines using a speed square. If you have made incorrect lines, you can easily wipe them off with acetone and start over. If making bend lines and straight lines, use different color markers to know which is which.
When you are making a box or pan or something similar, you end up with a 90 degree where you have to bend the metal. You need relief at the corners or it will bulge. You can do that by drilling a hole right at the corner. Use a center punch to make a divot in all the places you need holes.