Drawing cylinders, like drawing circles, is easy stuff. But drawing perfect cylinders, minutely calibrated edges and angles and all, is often impossible unless you have the right method and the right tools. Rather than lazily sketching your way to a mediocre cylinder, why not improve your drawing and drafting ability by crafting a perfect one?
Watch this drawing tutorial to learn how to draw a cylinder inside a prism. The prism acts as a container and guide for the prism to come out even.