Pitch corrections (right amount of Autotune effect plugin if compulsory)Equalizer (EQ)
Compressing
De-Esser ( reductions of sibilance sounds )
Multiband compression
Stereo expanding and panning
Level balancing
Automation (in terms of volume, effects sends, etc.)
Vocal Timing corrections
Audio repair or noise reduction
Reverb, Delay and other effects
Pitch correction with vari audio
Mastering
Dynamic EQ (if compulsory ) Multiband compression (if compulsory) Saturation (if compulsory) Stereo widening a mix with MS Processing (if compulsory) Maximizing the loudness of the final mix (most important)