I've been doing home recording for three years and I want to share what actually helped versus what I spent money on chasing the wrong things.

The biggest single improvement to my recordings came from acoustic treatment in the corners of my room. Not full studio treatment, just rigid fiberglass panels I built myself for about $80 total. The before and after on my room recordings was embarrassing — I couldn't hear how bad my untreated room sounded until I fixed it.

Second biggest was learning to use the gear I already had properly instead of upgrading. I spent six months reading about preamp upgrades before someone told me my interface preamps were fine and I just didn't know how to use them. They were right. Learning to set proper gain staging eliminated the noise floor problem I'd been blaming on the hardware.

Third: a decent pair of closed-back headphones for tracking. Not for mixing, but for getting clean takes without bleed.

What's your single best home recording improvement for under $100?