Good thread here explaining why most of the speculation on the internet about mastering to lower levels to “optimize” for these streaming services isn’t really what most ME’s are doing and isn’t really a good idea. Targeting Mastering Loudness for Streaming (LUFS, Spotify, YouTube)-Why NOT to do it. You could take it further and say dont worry about RMS / LUFS in general and just use your ears but it can definitely be useful to check some reference tracks in the same genre and measure the RMS / LUFS of those to get a sense of what a reasonable target is. If your references are modern dance music I’ll bet it’s louder than -14 on LUFS or RMS