Mixing And Mastering: MIXING:
1st off, when someone asks us to mix a track, song, or beat, to a person who is actually educated in this field would balance out the track so that nothing is drowned out or overwhelming and bring up the "references" to industry standard.
Note: if you ask for a mixdown and you have already mixed it improperly, futher mixing is pointless and it is better off to mix it down again from the start.
MASTERING:
When someone asks us to master a track I have to sound like a geek and explain to them the difference. You usually dont usually master one track, you master all of them and...