[Psyladine]

Here's a free method that's twice as much work but produces great results:

immediately after composing, for each step and nested step, write a line or two of what its place in the code is for. Write it as though the code is broken and you're following the imaginary line threading through, explained as if to your rubber duck.

Then, having written out the business logic map, look at each written step and see if they're just a description of the logic "iterates through file, passes hits onto nextFunc" and you can safely delete those. They're just glue, really, holding processes together.

What you'll have left is skeletal comments that are restricted to "we did this because this stackoverflow post gave the solution" as well as those mental maps of the solution in your head, which is really what comments are for, future programmers to grok your state of mind and thus better implement their code changes.