[dannysu]

Giving a tech talk is a great way to learn things. Having to explain something to another person forces you to clarify your own understanding of something.

I sometimes would force myself to do a talk to learn.

One suggestion I have is to find something that you still find "magical", then learn about it. At the end you will have a topic worthy of a tech talk. E.g. how does a JavaScript minifier work? or how does smartphone device image (ROM) format work?

By "magical" I mean you don't understand how it works and it does things almost like magic. Computers are not magical, so you can gradually turn magical things into in-depth knowledge.

Chances are that things you find magical are equally magical to other people. And then to get started, maybe start within your company or go to meetups with relevant topic.