I use comments to break up a large block of code into smaller chunks to explain what is happening / where we are in the process.

I used to be a firm believer in self documenting code, but that approach often led to a large number of functions that only get called once. So lately, I have been just putting a comment line where I otherwise would have refactored the code into a function, and I feel that it has made my code a lot easier to read, and understand.