In a narrower sense of the word, one technique I developed early on in my career that I don’t see mentioned very often is exploratory debugging. At its most basic, you run the program, look at the output and find the output string in the source code. Then you set a breakpoint there, and go again. You’re now in a place where you can start understanding the program by working backwards from the output.

One thing that makes me sad about the pervasive use of async/await-style programming is that it usually breaks the stack in a way that makes this technique a bit useless.