If you want to make
your own watch can buy a case/movement/hands then over time put them together. This is not a trivial task and has a lot of geek cred associated with it (and at the end of it you have a mechanical watch).
However, what would it mean to make a watch from scratch with no off the shelf components? Just think about it for a minute. You would have to buy tools and machinery, learn the techniques to use them, understand in a deep and significant way the workings of a mechanical watch, design a movement, build each individual movement component by hand, machine the case by hand , design and turn the dial, machine the hands then assemble and test the watch. What would that actually involve? What skills would you have to develop and how long would it take you to get to the point you could build something that actually worked, let alone something someone would be willing to pay hundreds of thousands of dollars for?
An Englishman called George Daniels did just this, and in a series of videos on the brilliant Web Of Stories he talks about his life and his work. If like me you enjoy octogenarian horologists in cardigans talking at great lengths about lathes this is right up your street! — via Wrist Watch Review