How I know when the track is well mastered?
Hi. When working on new track is reccomended to use a reference track. Your reference can be any track that you like and you wish your new tune sound similar in quality, loudness and maybe in some specific elements. The final audio volume and other parameters also depends on the futher use of the audio like distributing on social platforms, streaming services etc. Keep it clean, try to avoid interference in frequences between different musical parts of the track, check the volume levels, no clipping … But remember, it is your cration and only you know and feel how your music should sound in general.