You can fiddle with your master fader but that is like jerking off during a date.
Yeah, get everything else right, and your master will COME UP to -6db.
Really what I recommend is work up, always up, never really turning down. Get to where a mix is okay, everything is balanced properly, and where you’ve still got a lot of headroom left, then start applying texture and hair to your sounds, breathing life into them, this will raise the peaks even further, so the point is to start well enough below that.
Re starting with the kick, yes I used to religiously do that, but that was a little earlier in my learning about this. I still look at my kick level when setting my monitor level (which is a lot more dynamic now, used to just be in the studio, in a static listening environment so everything was reproducible), and still check to make sure my kicks are not over -12db. But, my workflow has changed a bit since then. I used to use the kick as the grain that started the crystal of the song - everything would be based upon the structure of the kick, so tonality, dynamics, tempo, volume. I’m still using kicks, but I’m doing a lot more with breaks now, so they usually have a dynamic already set, like their kick/snare relationship is usually pretty set, and what I like, so I don’t fux with that.
Analogy:
Think of loudness like brightness of light. In the end you want to have a bright picture. You start from complete blackness, you start adding light sources. If the lights you add are too bright, or are as bright as they can be (0dbfs) there is no room to go from there. Everything will be in relation to that brightest thing, everything will be degrees darker than that brightest thing.
Best to start in darkness and bring your lights in, but keep them dim, create the picture, the relative balance of lightness and darkness between the elements, and as you do that, you increase the intensity of your light, you increase the saturation, the color richness, at the end you begin to lose some detail, but you trade that detail for brightness, and bringing brightness into the textural shadows where interesting things happen (that is limiting, that last part).
Really look forward to hearing your tunes. You’ve got the art down, imo, if your craft comes up, you’ll be decidedly off the chain.