We need to know who our potential fans are. What do they do in their free time? What do they talk about? Where they listen to music? Where do they discuss the music?
We need to know this to understand where and how we can address our audience.
It’s pointless to promote our conceptual album consisting of sounds of dying icebergs combined with rhythmic sounds of factories and funk samples in a Justin Bieber fan club.
We can use our FB and Instagram insights to understand some basic info about our audience. If we don’t have an audience, we can become a member of niche “genre” Facebook groups, Subreddits (for example, r/progmetal), YouTube Channels, Twitch Channels. In those groups, we can find sources for niche blogs and channels that we can approach when we have a release. There we can find Spotify playlists that we can apply for. But we need to engage with people in those groups. Blatant promotion is undesired, especially on Reddit. I chat with people occasionally in music marketing groups on FB.
We should update our info at the Metal Archives (if it applies to us). It is the main resource for metal music. All band bio, photos, links etc. should be fresh and tops. The forum at Metal Archives is a great place to find our potential fans.
And again, we need to find who our fans are and where to find them. Once we know that, we prepare a marketing campaign around that info.
Each band is a separate case, hence my general writing. The good stuff is in the details. We can have a Skype call for a consultancy session. Just write to firstname.lastname@example.org