Mix readiness
Prepare your mix for mastering.
A good pre-master is intentional, technically clean, and still sounds like your record. Leave mastering room to refine it; do not make it rescue preventable problems.
The final-listen checklist
Keep the decisions that belong to the mix
Vocal level, kick-to-bass balance, automation, arrangement, and effects timing are mix decisions. Mastering can rebalance a finished stereo file, but it cannot independently move one instrument without affecting others around it.
If the request names one instrument, return to the mix first. If it describes the record as a whole, mastering may be the right stage.
Listen once without touching anything
Play the full song from start to finish and write down every distraction. Make one deliberate correction pass, then export and stop. Repeated last-minute changes can trade a known issue for a new one.