At one time I kept a folder full of what I called skeleton extensions These were stub-like php files which outlined the basics of each of the types of extensions, for use when I wanted to create a new one. This came in handy, but quickly fell out of date with best-practices (around 1.16.0 if I remember.) Since then I just go to the appropriate page for the extension and follow the directions (typically copy-and-pasting code into my editor.)
I wonder if there is any interest in keeping some of these skeleton extensions around, or maybe writing a maintenance script that would produce a skeleton?