Here's the short answer:Pull down the ceiling in the downstairs unit.Add insulation to the joist bays (Roxsul is best)Run resilient channelHang 2 layers of 5/8 drywall on the resilient channel with "sound caulking" between the layersIt's a big job, but very effective.

Wood chips, rocks, very resilient plants, etc.... they won’t keep it up.

If you want to take it to the next level that would incld safe-n-sound + resilient channel.

Otherwise, depending if they are side by side or up/down units, spray foam insulation (high grade purple stuff) is very good at sound proofing or using resilient channels with soundproof drywall and Roxul is good.Here's an in-depth site I found: https://www.soundproofingtips.com/soundproofing-materials/

In my basement, which has nothing between the joists, but does have the resilient metal strips, footstep noise is the issue.

I haven't done this before, but am interested in learning, so I'm leaning towards giving it a go myself to start and falling back on a manager if it becomes too time consuming or annoying.2) Common fixesIs there anything I should fix, or make more resilient before renting?

Have you considered the resilient vinyl flooring.

But I believe in the resilience of Americans to get their house in order.........they have the best economists and brain power.

In 2010 U.S. bank stress tests were held to determine the resilience of banks in the event of a possible euro zone debt default.

I hope it works out and I should know by next week but either way, I'm resilient.