If you don't already know pop-rivets, this is one tool you should become familiar with. The pop rivet looks a bit like a funny nail. You drill precise holes through two pieces of thin material that you want to join together. This is commonly used for all kinds of sheet metal work, but can also be used for any fairly ridged sheet material from leather to arborite.
You insert the rivet into the holes of the two materials while holding them tightly together, put the shaft into the pop-rivet gun and it will then force the "nail" through the rivet until it "pops" off. The head of the nail fattens the other side of the rivet. One advantage of this system is that you can put in a rivet in a place where you can only work from one side, like in a lot of autobody work. But you do get a better joint if you can put a special washer on the back side before popping the rivet as the washer then prevents the rivet from possibly pulling through later.
By the way, you can now get coloured rivets to match painted sheet metal, like white aluminum trim.