Stopping for 30 seconds to come up with subpar copy is usually worth it vs using some sort of placeholder that you need to come back and fix later. When I know the copy is awful and that I need to come back and replace it, I put in a comment that says

  # COPY_REQUIRED

As long as I'm consistent about the tag that I use, I can easily search my project for my tags and fix before launch.

Similarly, I do a fair amount of presentations, and I always put in huge red letters a note to update the metrics, provide a source, etc. It's hard to miss when doing a final flip-through.