If I try the solution to a question I ask and it doesn't work, what is the best way to show the failed attempt? For example, following the directions of this answer led to no affect and rather than respond with an unhelpful "it didn't work" I want to show exactly what I did (which involves a number of different files) to see where I inevitably went wrong. Obviously I can't do this in a comment, so the only other options seem to be a new question or editing the original question with an addendum, although I don't know which of these (if either) is appropriate.
If you were not the person that asked the original question, you can ask a different question where you link the original question and the answer that you tried but failed.
You should also offer additional info if you have any.
Something like "I tried what was answered here, but it fails when I'm doing this".
Or anything else you think might be valuable.
There is no point in adding the same question if you don't bring anything new to the table.
If you asked the original question and the answers didn't work, you can mention that in the comment, or you can edit your question saying what you've tried and what problems you met after that.