Does the song have direction? Are the changes between sections intentional?
★ Mix
Low End
High-pass melodic elements: vocals, synths, pads, leads, keys. Start around 80hz, use your ears
Check for mud. Anything washed out? Cut low end or low mids with EQ or a filter
Reverb and delay tails can generate mud. Cut low end inside the effect parameters. Don't forget return tracks
Balance
Listen overall. Anything too loud or too quiet?
No section should feel unexpectedly louder than the last
Inconsistent synth or vocal volume? Try a compressor to tame peaks
Check for sharp or harsh sounds in the highs. Snares and hats are common spots
Is reverb decay too long? If elements sound washy or cluttered, try shortening the decay time.
Final Mix Check
Select all tracks and raise the volume together to preserve your relative levels (or lower if you're clipping)
No clipping on the master bus
Listen on multiple speakers: studio monitors, headphones, phone, laptop, car, bluetooth. Each reveals something different. You may find yourself going back to make mix adjustments and that's normal.
★ Quick Master
Mastering is final polish, not fixing problems. If something needs fixing, go back to the mix. Constantly compare to your reference track.
Add saturation on the master bus. Keep it light, less is more. A good rule: you shouldn't hear it when it's on, but you notice when it's off. Ozone Exciter is a good option.
Add a limiter after. Use it to bring your volume up to a similar loudness as your reference track without squashing the dynamics
"You mix with your ears, but your eyes are a great tool."
★ Reminders
Use a spectrum analyzer on your song and your reference to see if you notice anything vastly different. SPAN is a good free option
If you get stuck, take a break. Even 10 to 15 minutes resets your ears