[auiya]

> Use a dozen cheap foam panels to reduce unwanted room sound (placed closer to the vocals/instrument depending on situation). I tacked mine to a sheet of plywood so that it could be moved around.

You're talking about bass traps. They're an essential for recording in most every room. Here's a great video for how to build some quite effective ones for cheap. (I'm not affiliated w/ this guy or his channel). https://www.youtube.com/watch?v=dZV-gxVpkGk