soundproofing for urban people

I found a YouTube video posted by Tone N.W. and it annotates the steps he took to soundproof his bedroom ceiling after his upstairs neighbor tore out her carpeting and began walking around on bare hardwood floors above his home. As you know, hardwood floors can be your worst enemy. A hardwood floor that's nailed directly onto a subfloor and then directly on top of wood joists is like a microphone into the rest of the building, and that impact noise travels through all the framing and right into the adjacent rooms (or apartments). He said that he learned everything he needed to know from this document from The Soundproofing Company in Michigan. Here's what they did: They tore off the original drywall ceiling. It looks like a previous owner had added cross strips of wood on the joists already, and they removed those too. (If you read his notes, it sounds like he regrets the extra labor in this step.) He and his wife cut drywall and added it to the upstairs subfloor in