* Listen to references that you want your mix to sound like.
* Send your project to your mastering engineer in advance if possible to get feedback on your mixes. Your project will thank you if you make the most of your relationship with your mastering engineer.
* If your project has more than one song, sequence your mixes in a digital audio workstation and bounce around from mix to mix. Are the vocal levels consistent? How about the drums and bass?
* Export your mix as a WAV or AIFF file at 24 bit, using whatever sample rate your project was mixed with.
* Audition your mix to be sure there are no digital glitches from the bouncing process. Your mastering engineer can sometimes cut them out but not always.
* Before uploading your project for song mastering, put all of the mixes in a folder and zip it. On a Mac, you can zip your folder by right-clicking on the folder and selecting “create archive” on the pop up window. On a PC, you can use a program like Stuffit.