Related advice would be to annotate every stack effect with a comment, no exceptions.

Back when I was into Forth, I had this wild notion of adding a stack checker, defining two additional comment words which would be aware of the stack effect of all core words, and require a stack effect to be defined for every new piece of vocabulary.

Never did anything with it, don't write Forth anymore, doubt I will again. I still think it's a good idea though, so I like to put it out there.