Mastering
Mastering is the last listening pass before a song leaves the studio. At home it is usually done by the same person who mixed, which makes the job harder: you need distance from the mix, a reliable reference level and a clear idea of what the streaming platforms will do to the file.
These guides cover what mastering can and cannot fix, how loud a master needs to be once normalization is applied, how a limiter and true peak metering work, and where mid-side processing helps.

Mastering at Home: Preparing, Processing and Delivering a Track
After reading, you will be able to prepare a mix for mastering, build a short and careful processing chain, aim for sensible loudness and true peak values, and export the files a release needs.

Getting Your Mixes Louder Without Losing Punch or Clarity
This guide shows where perceived loudness really comes from, how to read LUFS and crest factor, and how to raise the level of a mix in stages so it stays punchy after streaming normalization.