With the reliability of modern electronics vacuum tube making is a dying art. Here are some great videos demonstrating the laborious steps that go into creating them.
“Vacuum tubes mostly rely on thermionic emission of electrons from a hot filament or a cathode heated by the filament. This type is called a thermionic tube or thermionic valve. A phototube, however, achieves electron emission through the photoelectric effect. Not all electron tubes contain vacuum: gas-filled tubes are devices that rely on the properties of a discharge through an ionized gas.”